Doctor Who/Recap/S17 E4 Nightmare of Eden

"Romana: I don't think we should interfere.

The Doctor: Interfere! Of course we should interfere. Always do what you're best at, that's what I say."

The Doctor and Romana arrive on a space liner orbiting the planet Azure, which has just been impaled by a private spacecraft due to an accident leaving hyperspace. The accident happened because the navigator of the liner was stoned out of his mind on a horribly addictive illegal drug called vraxoin, and it appears somebody onboard the liner is smuggling it.

To make things more dangerous, a biologist named Tryst who is travelling aboard the liner is carrying a machine of his invention that keeps samples of alien ecosystems in pocket universes for observation. The effects of the hyperspace Tele Frag cause a group of monstrous predatory beasts called Mandrels, from the misleadingly-named planet Eden, to escape and start slicing people up.

The Doctor and Romana are further endangered when the brutal and stupid local border guards assume that the Doctor is a drug-dealer because he was carrying some vraxoin he discovered around as evidence.

Eventually the Doctor manages to separate the two ships, with help from the TARDIS's systems. The drug-smugglers turn out to be Tryst and Dymond, the owner of the smaller ship. It turns out that vraxoin is made from decomposed Mandrel corpses, which was why Tryst was keeping them in his hi-tech zoo. The Doctor decides to return the Mandrels and the other specimens to their original planets.

Tropes

 * All There in the Manual: The weird glowing thing that knocks Romana out is explained in the novelisation as a venomous Eden insect.
 * Bad Cop, Incompetent Cop: Fisk and Costa
 * Battle Discretion Shot: The Doctor's fight with the Mandrels as he lures them back into the CET projection. The subject of much condemnation then and since by certain fans.
 * Call Back: The CET machine and the Mandrels are very similar to the Miniscope and the Drashigs from "Carnival of Monsters".
 * Clear My Name / Not What It Looks Like
 * Death World: The misleadingly named Eden. (The novelisation makes it clear that this was deliberately sarcastic.}
 * Drugged Pilot
 * Drugs Are Bad
 * Earthshattering Kaboom: The original source of vraxoin was a fungus, but the social havoc caused by the drug was so horrific that the planet it grew on got glassed.
 * For Science!: Tryst's attempted justification for drug-dealing is to get funding to continue his vital research, to the Doctor's utter contempt.
 * Friend or Foe: Stott and the Doctor initially mistaking each other for the villain.
 * Good Scars, Evil Scars: Stott has the anti-hero variety.
 * Hell-Bent for Leather: Fisk and Costa, verging on Leather Man.
 * Herr Doktor: Tryst, although he's closer to the older unworldly Dichter and Denker German stereotype.
 * Judge, Jury, and Executioner
 * Man-Eating Plant: The centre of a Big Lipped Alligator Moment when the Doctor gets pointlessly attacked by one while wandering around the Eden projection, and defeats it by biting it.
 * Pinata Enemy: Monsters that turn into a highly sought-after narcotic when you kill them.
 * Portal Picture: The CET machine
 * Reasonable Authority Figure: Captain Rigg, until he gets dosed with vraxoin
 * Reports of My Death Were Greatly Exaggerated: Stott.
 * Scotty Time: Romana gets this when the Doctor asks her to modify the CET.
 * Sinister Shades: Tryst
 * Slipping a Mickey
 * Tele Frag: Occurs while leaving hyperspace rather than through teleportation, but still an example.
 * Undercover Cop Reveal
 * Very Special Episode: The Doctor confronts drug trafficking.
 * What the Hell Is That Accent?
 * The X of Y