The Hitchhiker's Guide to the Galaxy/WMG

The question doesn't exist, nor does the answer
Apparently, if we find the question and the answer, the universe will be replaced by something infinitely more confusing. However, this has already happened at least once (we think), and has probably happened multiple times before that, too. If you do that enough times, eventually the result will be something that makes no sense to anyone including its creator, or something with no meaning. No meaning, no question, no answer. 42 is a number pulled out of Deep Thought's and Douglas Adam's collective ass.

The computing power of Earth
Now, we know that it took the Earth 10 billion years to (almost) determine the Ultimate Question. And it is self-apparent that the Ultimate Question would be 42 characters (where "characters" are lower-case letters, space, period, and commas). From this, it is easy to determine there are about 8.3x10^61 possible combinations. Further, using the fact that when the Answer was orignally revealed that computers were 100 less powerful, it is easy to calculate that at the rate these computers were going, 2,000 combinations a second, that the Earth was approximately 4.2x10^42 times as powerful as the computer used to write the Hitchiker's Trilogy. Now did I just blow your mind or what?
 * What are you talking about? What do you mean, "42 characters"? What is this about the trilogy being written by a computer?
 * Smile and nod, smile and nod...
 * The trilogy wasn't written by a computer, but on one. Douglas was a great fan of Macs (well, someone has to be) and was the first person in the UK to buy one (The second? Stephen Fry), and he used it to write his books.
 * The first three Hitchhiker books were written before 1984. He'd have used an earlier variety of Apple. That probably made writing the Interactive Fiction version of the book much easier...
 * The first three books were written on a typewriter. Adams's enthusiasm for computers came later.
 * The answer isn't 42 characters long. The answer just is 42.
 * If the question is 42 characters long, it's probably "How many characters are in this question??".

Earth has already worked out the Ultimate Question, and one human expressed it - Bob Dylan
How many roads must a man walk down before you can call him a man? 42. Bada-bing, bada-boom.
 * The universe wasn't destroyed after you figured that out. Since knowing both the question and the answer are supposed to destroy the universe and replace it with something infinitely more confusing, you didn't find the question and neither did Bob Dylan.
 * Hello? The Sixties? "Bob Dylan destroyed the universe and replaced it with something infinitely more confusing" is as good an explanation as anything for what's been happening since 1963 (when he released the song).
 * Man, this could be true!
 * The song, with the question, came out in 1963, and the first book, with the answer, was released in 1979. Wouldn't that mean that the answer is wrong since the question came first?
 * The scene with the answer is set millions of years ago
 * And the question was canonically given. "What do you get if you multiply six by nine?". Context is the bitch.
 * But in context there's nothing that proves that's the real question (in fact, it can't be).
 * Can in Base 13.
 * But doesn't. Might elseways, though.

We get told the Ultimate Question in the first book.
OK, Marvin has a brain the size of a planet. He tells us this. To prove how much cleverer than human he is, he asks Arthur Dent to think of a number. When Arthur does, Marvin tells him that he is wrong.

That is it.

The ultimate question is "Think of a number."

""...There is another theory which states that this has already happened.""
 * If that was it, then the universe would have destroyed itself and been replaced with something even more inexplicable. It's "Think of a number" in the form of a question. Until someone manages to put that into the form of a question, that possibility can't be ruled out.
 * What number am I thinking of? Oh ****.
 * "If that was it, the universe would have destroyed itself and been replaced with something even more inexplicable." Done! What better explanation is there for the Universe we have now?
 * No, I doubt that would happen. You likely have to know whether it's the question for the meaning of life to be reset. Also, you probably have to be an organism, since Marvin knows both the question and answer.
 * Erm, no - Marvin asks that of a sentient mattress in his first few scenes in the third book, "Life, The Universe and Everything".
 * If the Guide Universe is a separate section of the Whole Sort of General Mish-Mash from our own (with its own question and answer), then you know what the man said:

The Universe's Ruler's Cat in The Restaurant at the End of the Universe IS God.
...Well, at least in that universe cross-section of the Whole Sort of General Mish-Mash. Think about it. If this guy rules the universe, then there has to be some connection between him and God. If he names his cat The Lord, then it only makes sense that it's the real thing. And, considering what goes on in that section, it's not that unlikely.
 * You mean he's Ceiling Cat?
 * Well if if he's God, and God spelled backwards is Dog, and he's a Cat so..... There's a connection here somewhere.
 * He's Satan? After all, cats supposedly dislike dogs... But then again, why is the cat called The Lord? A Red Herring?
 * Dog is God spelled the opposite direction with means that God is the opposite of Dog. And Cat is the opposite of Dog. Therefore Cat and God is the same thing.
 * By that same brand of logic you could say that dog is the opposite of god, and dog is the servant where man is the master. Master and servant are opposites, therefore man is god.
 * Exactly, man is God, you state the last point as if with disbelief.
 * OW ow ow ow ow ow. Why do I feel like I drank three Pan Galactic Gargle Blasters after reading this?

The real question is not "What do you get when you multiply six by nine?"
Arthur is, presumably, a descendant of the Golgafrinchans. But they weren't created as part of the Earth. Therefore, there is no way that they can have the answer stored in their minds. The ape-men, however, managed to produce "42", which means that they are part of the computer. Therefore, the question is stored the apes' minds, but not in Arthur's or the Golgafrinchans'. The fact that the question gives a different answer than what is calculated is not an error on the computer's fault -- it's a result of the humans not originally being part of the computer.
 * But Marvin said that he has seen the question in Arthur's brainwaves. So, possibly, modern-day humans are interspecies offspring of the Golgafrinchans and the Native Earthlings.
 * The question Marvin saw was "What do you get when you multiply six by nine?" Since he's The Eeyore, it made sense to him that the ultimate question would be meaningless, and the ultimate answer would be wrong.
 * Re-read the book, dum-dum. Arthur clearly states, in the final scenes of the second book, that the Question that Marvin read must have been a warped or wrong version because it came from a Golgafrinchan descendant.
 * That's not in every edition.
 * Once the Golgafrinchans were integrated into Earth's environment, they became part of its system. It makes just as much sense as adding software to your computer.
 * Albeit buggy and dysfunctional software, because the Golgafrinchans are idiots.
 * More like random malware adding itself to your computer, and your computer adapting to use it. Although since this was a fiendishly complicated system designed by Deep Thought, it can't be ruled out.
 * Because the Question which Arthur would come up with (being descended from the Golgafrinchans) is warped, that must surely mean that the real Question is a purer or more correct version of that - for example, "What Do You Get When You Multiply Six By Seven?".
 * DO NOT ASSUME THE QUESTION IS IN BASE 10, PUNY MORTAL!
 * The Question actually works in base 13 (what is that, triskadecimal?).
 * So...is the answer 13?
 * Ford said the human-Golgafrinchian version of the question was probably either "the wrong question" or a "distortion of the right one". As it turned out, it was both: a distortion of the wrong question (what's six times seven).
 * Ford said the human-Golgafrinchian version of the question was probably either "the wrong question" or a "distortion of the right one". As it turned out, it was both: a distortion of the wrong question (what's six times seven).

The Ultimate Question is something on the order of, "How many times has this question been discovered/asked?"
Which of course means that discovery or asking of the Question will cause the Answer to increment. Cue the Universe reconfiguring itself around the new Answer.
 * Presumably, Deep Thought did know the Ultimate Question; but he knew that, if he said it aloud, he would negate his own existence. So he makes a new computer to tell them ten billion years later, when he would probably not have to worry about it.
 * If that is the Question, this may explain why the Answer seems to have inflated to 47.
 * Wait a minute. If this is the question, wouldn't that mean that the universe would be reconfigure itself at an alarming rate, which would mean that the answer is infinity.
 * No, because we wouldn't notice. It could be at 44 by now, or it could be at 53, or it could be in base 13 . As the Answer increases (and thus gets further from 42, and eventually gains more and more digits), the number of times the correct answer is asked for the question in a given time frame tends toward zero.
 * Congratulations

The question was discovered in So Long and Thanks For All The Fish but was not revealed by Douglas Adams.
The Earth was destroyed 5 minutes before the Question was supposed to be computed. When the Earth was, that means that the Earth was able to complete the Question in time, since the Earth was destroyed  several months after. The reason Adams didn't reveal the Question was that A. revealing it would destroy the universe, and B. Adams was too busy writing love scenes between Arthur and Fenchurch.
 * This troper is okay with that.
 * Heavily implied by the respective prologues of The Hitchhiker's Guide to the Galaxy and So Long and Thanks For All the Fish. Presumably Fenchurch was the one who discovered the Question and this is what caused her momentary mental breakdown, resulting in her collapsing face-first into an egg salad sandwich. Now, when Arthur asks her if the number 42 has any particular meaning to her, the universe is not destroyed because A. she forgot what she had learned in that cafe, and B. she doesn't know what significance the number has to Arthur, namely that it's the Answer.
 * That wasn't Fenchurch's revelation - her revelation was a way that all of lifekind could live together in peace and harmony with no need for conflict. It's separate to the Question.
 * Since all that conflict and discord was part of the computer's search for the Question, it's quite possible that Fenchurch's idea either was the Question, or was one of the critical steps on the way to finding it. So while she might not have known the Question, maybe the first person she explained her brilliant idea to would have figured it out?
 * You're both wrong. Fenchurch's revelation was God's Final Message. That's why when she sees it she says "Yes, that was it"
 * No, but remember that in "The Restaurant at the End of the Universe" the result that the Earth would have given is revealed - and it's "the wrong one, or a distortion of the right one" because of the interference of the Golgafrinchans. I do think that the Earth did complete its computations five minutes after it was brought back into existence, but the Question it gave was "What do you get if you multiply six by nine?" And because a) We already heard that, b) It took place approximately 5 months before the beginning of the book, and c) It wasn't important to the book's plot, Adams left it out.

The unwritten sequels would have seen the gang rescued by Lig Lury, Jr.
Lury, you will remember, was the Guide editor and disciple of the Lunching Friars who had disappeared while on a protracted luncheon break. It's (finitely) probable that he hooked up with Slartibartfast's restaurant ship Bistromath and spent the next hundred years touring the best eateries of the galaxy. Perhaps Adams established Arthur's sandwich-making skills and Ford's restaurant critic gig to provide a reason for a famished Lury to swoop in and save them before the earth blew up.
 * That actually makes a lot of sense...
 * Especcially since the Bristomath has that "Somebody Else's Problem" Feild, which would make how they got in to save the gang and them back out again exactly that.
 * Well, we'll find out soon, won't we?
 * It didn't happen, but getting rescued by was even more surprising.
 * If somewhat disappointing. But then again, I was hoping the Dolphins would do it.
 * In the radio show, the Babel Fish saved them.

People really do come to sing songs to The Lord
and the ruler of the universe is right not to believe in anything.
 * The Lord really is the avatar of The Ultimate Sentience. The six small black ships are really not ships, but portals, about the size of a chariot of fire invisible to the mortal eye. The entire series was set in motion by The Lord for fish, and the Guide v.2 is some sort of Satan, using a perverted form of The Lord's method of causing the Whole General Mish-Mash to have already been otherwise. (The Guide v.2 is actually an alpine chough rather than the vague, bird-like weirdness it claims to be).
 * So... Guide V.2 is Mary Malone's deamon from His Dark Materials? Well, she's screwed then.
 * Additionally, where did you get the Pan Galactic Garble Blaster you drank during this?

The person that figured out both the question and the answer would have reality bending powers.
Thus, destroying the Universe and recreating into something even weirder depended on their emotions, wasn't really automatic. And such person would need to be emotionally unstable to figure it out at first, making it practically automatic in first place (I know it's confusing, but understandable after a certain point of view). So, I guess that's how Haruhi got her powers and rebuilt the Universe through boredom (the Universe always being on risk of becoming even more weirder than the rebuild isn't mentioned in the books, but it's part of the New Order's weirdness); the fact that she doesn't know that she have powers is one more proof, how was she supposed to know that she knew the question and the answer, and those would give her such powers?


 * The Earth is the Data Overmind.


 * Maybe Mikuru comes from a future a little down the track and actually has access to computers like Deep Thought, which is why she doesn't know how to use modern human technology.

Marvin's Brain is/was the Earth
Marvin continually claims that his brain is the size of a planet; this is because it is the Earth computer, or is connected to it. He is infinitely depressed in part due to the fact that he knows that the Question discovered by the Earth is the wrong one, and so he is being kept alive for a completely pointless purpose; in "So Long, And Thanks For All The Fish", in which the Earth Mk. II has been installed, the dying Marivn recalls that every part of him has been replaced except the achy diodes down his left side.

Deep Thought was just messing with the scientists.
It spent 7 million years writing the first true random number generator, and half a million years thinking of what else it could do. It didn't really think they would actually build Earth. (Although, considering that it would have been the universe's first true random number generator, 42 could really be the answer, by accident. and the question is the program.)

God's last message to his creation is different for every sapient being who reads it
Arthur's reaction seems to indicate that the had discovered the question, but "Apologize for the inconvenience" doesn't match the answer. It seems that the message is a message to every individual being rather then civilization as a whole.

The sixth radio phase
...would've been called the Sexaholic Phase. Unfortunately, countries with strong Moral Guardians would've seen it changed to merely the Hexagonal Phase.

And Another Thing was written by Douglas Adams possessing Eoin Colfer from beyond the Grave
Perhaps you may be thinking "But why didn't it come out earlier then?" Obviously,in addition to finding a good person to posses, possession is very difficult to do.Adams,after figuring out how long it would take for him to do this,had Colfer announce that he would be writing book at a point that would be considered an average amount of time for writing a book of such length.
 * Its not that it was painful. Its that Adams, even after death, has a looot of problems with getting things in on time. Colfer only announced things when Adams was far enough along for Colfer not to get yelled at.
 * If you have to ask why it took so long, then clearly you are not aware of Adam's attitude towards deadlines.
 * It must be said that Adams thought it extremely unlikely he'd be doing anything after his death...
 * Besides, we all know he's not dead. He faked his death to avoid having to write any more HHGG books, and is currently hitch-hiking across the Galaxy with Ford and Arthur, despite being supremely rich due to the many miss-purchasings of his books due to the shared title with the actual Guide. And/or doing something involving Eccentra Galumbits, the Triple-Breasted Whore of Eroticon Six.

The Heart of Gold from And Another Thing is not the same one from the previous books
At some point before (I want to say Life, The Universe, and Everything), it's mentioned that Zaphod Beeblebrox sold the Heart of Gold, and that's why the most improbable ship in the universe doesn't make an appearance in the last couple of books. However, the ship returns in the sixth book, albeit under a different description: instead of being shaped like an enormous white running shoe, it's shaped like a teardrop with slender protuberances running in a circular pattern around its perimeter (basically like an elongated Sputnik). This, coupled with the fact that Eddie the Shipboard Computer is MIA, implies that this is a different Heart of Gold, probably built by whomever Zaphod sold the original to. This also explains why Improbability Drives seem to have become commonplace as opposed to utterly revolutionary.
 * Colfer's description of the Heart of Gold is based on its appearance in the TV series.
 * Actually, there's like three different descriptions of the Heart of Gold. The running shoe, the tear-drop one from above, the flying tea cup from the movie, and whatever it actually was in the radio drama. Maybe they're all right, but it keeps changing shape because of the Infinite Improbability Drive? I mean, hell, it changed two missiles into a sperm whale and a bowl of petunias...

The Hitchhiker's Guide Galaxy was dreamed into existence by Alex Trebek.
And that, my friends, is why we know The Answer but not The Question. Bada-bing!
 * ...Alex Trebek. Okay then.

Buff Orpington is an Alternate Universe Mr. Prosser
He's fleetingly mentioned (in a Guide Note, I think) to be the descendant of some sort of Viking hero. Since Nano is inhabited by many Alternate Universe versions of just a very small and specific group of people, Hillman's cult, it could be that Buff Orpington is the equivalent of Mr. Prosser from the same Earth that spawned Fenchurch and Tricia.

The Bittersweet Ending of And Another Thing is actually...
Or at least trying to. It would explain his sudden and inexplicable (given his history and personality) Traveling Jones. He knew what would happen when he started traveling:
 * Doubt it. Arthur, I think, wouldn't be willing to leave his daughter forever, especially knowing how emotionally disturbed she is and we've seen in Mostly Harmless that he really does care for her.

Judiciary Pag, of the Krikkit Wars, is related to Zaphod Beeblebrox
Judiciary Pag, privately known as 'Zipo Bibrok 5x10^8', is a distant descendant and/or ancestor of Zaphod Beeblebrox, a logical extension of the Beeblebrox line past his great-grandfather Zaphod Beeblebrox the Fourth.
 * Again, simply pointing out something that is strongly implied, if not all but outright stated, in the book is not a WMG. There has to be some aspect of guessing in a Wild Mass Guess.

Fenchurch never disappeared.

 * No, they both disappeared. Relative to each other, anyway.
 * No, she stayed right where she was. He disappeared, into a world where the planet at ZZpl.Zα was a planet where more of the seawater cycled through the atmosphere, populated by the universe's most seemingly useless teacup boars.

Sooner or later, some Real Life numerologist is going to start doing some deep investigation of the number 42
So as to perform a Defictionalization of the concept that the number 42 is the Ultimate Answer to Life, the Universe, and Everything. It's entirely likely--but not necessary-- that it will involve base 13 in some way. Either way, such a numerologist would be unsupported by the Word of God (Douglas Adams anyway, who knows about the actual Gods?); but anyone who let that fact get in the way wouldn't be much of a numerologist or much of a true fan. Death of the Author, after all.
 * Already been done (seperatly) by a mathamatision at UCLA and a physisit at some British university. Nothing came of either.

Neither Arthur nor Fenchurch disappeared.
Alt-Arthur suddenly got the mind of Arthur-prime while they happened to be flying through the same point in space-time but different points on the axis of probability. See the preceding case of Doctor Rjinswan.

The ultimate question has something to do with Lady Gaga.
Gaga. G-A-G-A. 4242.
 * ...what?
 * Honestly, this would make sense...after a round of Pan Galactic Gargle Blasters and maybe a good hard face beating.
 * ...I'm not sure, but I assume that's "texting" talk. Letters correspond to the numbers on a telephone keypad. This, of course, assumes that all telephones the universe over use the same alphanumeric system and key placement.
 * You are so dumb. You are really dumb. For real.
 * PS same troper as above if you wanted to translate it number to letter you get DB. I am just putting that thought out there.

Arthur Dent is a reincarnation of King Arthur.
Arthur was said to awake from his slumber on Avalon to save Britain at its' time of greatest need, which as it turns out was when it was about to be destroyed by the Krikkiters along with the rest of Earth.
 * Saber is not pleased.

The Earth was programmed in C
There are a few order of presidence issues you need to be aware of in C otherwise weird stuff can happen. Consider the following code:


 * 1) include 


 * 1) define SIX 1 + 5
 * 2) define NINE 8 + 1

int main(void) { printf( "What you get if you multiply six by nine: %d\n", SIX * NINE ); return 0; }

Guess what the output is?
 * 1+ 5* 8+ 1=1+ 40+ 1=42... so... 42?
 * Except the computer would read it as (1+ 5)* (8+ 1)= 6* 9= 54... Thank you PEMDAS!
 * It actually works correctly on at least some compilers. So maybe Earth is just obfuscating the question to keep its inhabitants from discovering it early?

The island from Lost is where the Earth is finalizing the Ultimate Question Of Life The Universe and Everything
Over its running time, the Earth has worked back from the Ultimate Answer of 42, to get the five Ultimate Intermediate Steps of 23, 16, 15, 8 and 4. Just a few more calculations are required to get the Ultimate Question right. It has been said that if both the Question and the Answer are known it will cause the Universe to disappear and be replaced by something much stranger - the proximity of the Answer to a preliminary version of the Question is causing that to happen on a smaller scale, leading to all the tropical polar bears, smoke monsters and Epileptic Trees.
 * This is simply brilliant. The final season of the series is obviously after the Vogons destroy it. The passing of the leader of the island to the next is actually simply allowing the hyper-intelligent, pan-dimensional being to inhabit another form. The island was built by the computer to keep the Golgafrinchams away from the main program matrix.

The Heart of Gold is powered by Quantum Suicide
The Heart of Gold really just waits for quantum fluctuations to randomly deliver you to your destination. If you don't reach it in, oh say 5 minutes, it explodes and takes the entire universe with it. But, assuming the many worlds interpretation is true, there will always be at least one version of the universe where you made it to the destination and the Heart of Gold didn't kill you. Since that's the only universe you're alive in, it's the only universe you know about and from your point of view nothing ever goes wrong.

Has the added benefit of explaining the other weird effects the drive has, since maybe the drive is only checking for your destination and not other changes to the universe. And it lines up neatly with the way the drive is described working in the books. Finite improbability machines work the same way, but the reliability of the doomsday machine has to be at least equal to the probability of the event you want to happen, otherwise the bomb would just fail to explode rather than giving you the desired effect. Therefore, the Heart of Gold is really just an incredibly reliable doomsday machine.
 * From Arthur and Ford's perspective, getting airlocked from the Vogon ship was another successful quantum suicide.

== 1978/1979/1981/1984/2005 is the year of the Rapture, the Vogons are God, Ford and Zaphod are angels and Arthur and Trillian were the only ones to be redeemed. == Discuss. Besides the fact that yes, I left a few dates out of the header and "redeemed" probably isn't the word. I'm Jewish.
 * So you are saying that the Vogons created the Babel fish, got into an argument with man, lost and promptly vanished in a puff of logic?
 * That bit was in the Guide. Better citation needed.

The universe was destroyed and replaced with something even more inexplicable at the start of So Long And Thanks For All The Fish.
In the previous universe, which Arthur clearly remembers being in, the Earth was destroyed. Yet at the start of the fourth book, the Earth has returned, and even more inexplicably, Ford's detailed article on Earth for the Guide has no longer been condensed to the words "Mostly harmless." This Snap Back can only be the result of the Question and Answer being known at the same time. Since the prologues of the first and fourth books heavily point to Fenchurch having discovered the Question, the difference between the old Universe and the new one could only mean that she was somehow informed of the Answer as well.
 * This troper would place it right before Mostly Harmless. In the new universe, Arthur no longer knows how to fly (and there are several scenes where his ability to fly, and knowledge that people can fly, should've made a huge difference), Zaphod and Trillian's kids, not to mention Fenchurch, have all been retgonned out of existence, the Earth has now reappeared only because of random probability fluctuations rather than a reality warping project by the dolphins, and Ford and Arthur have inexplicably turned into bitter enemies whose reaction upon being reunited is to glare at each other in fighting poses and spit out "you" in unison. We already know Creator Breakdown was involved, so heck, why not cosmic breakdown?
 * Maybe it happened both times, somehow. That would explain the series' sudden transition from cynical to peppier at So Long, And Thanks for All the Fish and back to downright awful at Mostly Harmless (in-universe explanation, of course). Everyone knows about Adams' depression by now.

The computer Earth is based around fractals.
It would explain how Deep Thought can design something more intelligent than itself. It would also explain why fractals tend to show up in nature, and why humans find them innately attractive.

And Another Thing is Arthur Dent's Dying Dream.
The Guide 2.0's Lotus Eater Machine may or may not be part of the dream, but everything else is. The ending is Arthur realizing he's dead.
 * Why is everything always somebody's dying dream/hallucination/normal dream? Seriously, every single WMG of a major piece of fiction I have looked at includes one of these theories. Seriously, WTF?
 * The hell if I know. Some people haven't discovered the wonder of the Pan Galactic Gargle Blaster?
 * It's still better than it actually being canon.
 * Not to mention that it's actually reasonable considering how the previous book ended.

42 is the most terse, concise, compressed, and most importantly offensive vulgarity that Deep Thought could determine.
Because answering "Belgium!" to life, the universe, and everything would not have given life, the universe, and everything the response it deserved. Sub-guess: holding up four fingers on one hand and two fingers on the other is the most offensive guesture a being can make from a species with five digits per each of two hands (or four digits and the mousy equivalent of a dewclaw), as represented by the neologism "forty-two".

The Mice really aren't that smart.
If the Mice were so smart, why they didn't know the Vogons were coming? The Dolphins knew.
 * Smart and having good tech are two different things. The mice may have been smarter than the dolphins, but perhaps the dolphins had better sensor equipement and picked up the Vogons long before they showed up. Or read that destruction notice on-file at Alpha Centari... Not to mention, the mice were kinda busy making sure the Earth completed its calculations. The Dolphins were just there for the fish.

The end of the series would have revealed the Ultimate Question.
...because then Adams would have stopped writting Hitchhiker's Guide books and started on a new series. That is, the universe would have been destroyed and replaced by something different. Even if this wasn't planned in advance, it would have probably been the ending.

The Hitchiker Universe is actually the DC Universe
Deep Thought knew that if he gave the true Answer, his creators would search for the Question, find it, and destroy the universe. So he lied and told them 42. The actual Answer is 52, and the Question is "How many Earth's are there?". This also explains Fenchurch's disappearance- when the shuttle returned Earth's sector, it crossed into an alternate Earth where she couldn't exist and Earth itself was completely different. The Vogons had to destroy 52 Earths before their assignment from Gag Halfrunt was completed, which is why it was taking them so long.
 * On an interesting note, DC did publish Hitchhiker's comics.

Fenchurch Put the Ultimate Question and Answer Together on the Flight Home
She realized and then forgot the Ultimate Question during the Vogon attack, and then learned it again from God's final message to his creation near the end of So Long and Thanks For All the Fish. At that point the universe was safe because she didn't actually know the answer; Arthur had mentioned it to her, asking "does 42 mean anything to you," but she'd thought he was making a joke at the time. Then, when she and Arthur were riding home on the interstellar cruise ship, she remembered what he said earlier, connected 42 and the question together... and the universe was instantly erased and replaced by something even more inexplicable, which is where Mostly Harmless comes in.

The Guide Mk. II is Malphas, a President of Hell from the medieval and post-medieval Demonology.
Cobbled together from The Goetia: The Lesser Key of Solomon the King (1904) and Pseudomonarchia Daemonum (1583), using the layout from WMG/BlackButler:

He builds houses, high towers and strongholds, -The new/current/eventually-former H2G2 Headquarters. throws down the buildings of the enemies, - Again, the new/current/eventually-former H2G2 Headquarters, as well as Earth.

can destroy the enemies' desires or thoughts (and/or make them known to the conjurer) and all what they have done, - His ability to predict the desires of others because they just told it in their future, as well as the beginning of And Another Thing (with the simulations and their deactivation).

gives good familiars, - It's a raven-esque thing that uses Sufficiently Advanced Technology and acts exactly as friendly as is required for the situation for  (its official master) and   (its ultimate masters).

and can bring quickly artificers together from all places of the world. - Again, the beginning of And Another Thing, as well as the last half of Mostly Harmless.

Malphas accepts willingly and kindly any sacrifice offered to him, but then he will deceive the conjurer. - Just look at how it works for Random.

He is depicted as a crow that after a while or on request will put on human shape, - If I recall correctly, this is a potential option for its interface display, as are six crows, or an infinite lattice of perfectly-tesselated crows, or the shape of a color, or... or... or...

and speaks with a hoarse voice. - Its default voice.

He governs 40 Legions. - The s that do its bidding/tell it what to do.
 * Been hitting the Pan Galactic Gargle Blasters a little hard there, friend?

Hitchhiker's Guide takes place in the same universe as Doctor Who
It makes total sense if you think about it. The universe is a huge place, and who's to say that Time Lords and time travel doesn't exist?
 * Time travel actually does exist. Hell, it happens a bunch of times in Resteraunt at the End of the Universe (the "End" in the title is the end of Time).

The Golgafrinchans didn't replace the original inhabitants of Earth, and may even have been extinct by the start of Life, the Universe and Everything
Arthur thinks they must have survived, but given that most didn't make it through the winter and the last time Arthur saw the few survivors, they were sailing off on a raft (almost certainly completely unprepared for a sea journey), it seems quite likely that he's mistaken.

The humans were never supposed to work out the question in the first place - the dolphins were.
And maybe they succeeded.

The Guide Mk. 2 created the universe AND itself.
Think about it: the  may have thought that they comissioned the building of the guide, but it could have very well used reverse temporal engineering to make them do that. In this way, it is not really working for anyone, but for itself. Furthermore, in order to be needed and to be designed, the guide would have had to construct a universe in which the Vogons needed the Earths destroyed. It would have been easy to simply create this universe to suit its needs.