Bring Help Back

When a group of people in distress are stuck in one place, they will usually send someone to Bring Help Back. They might be suffering through The Siege, stuck in a Closed Circle, or they're too sick to travel and need someone to Find the Cure. For whatever reason, people are in danger and no one is coming to save them. So what do they do? If no Epic Hail is available, then they'll have to send one of their own out to get the help they need.

Similar to Gondor Calls for Aid, except that the process of calling is an adventure in and of itself. Typically, the nature of the threat is such that securing help is an Instant Win Condition -- provided you reach them in time, anyway. See also Bring News Back, which is sort of an inverse (bringing news to someone to help them instead of bringing them news that you need help).

Anime

 * Pretty much the basis of the beginning of Samurai 7, the anime reboot of Seven Samurai. Three people are tasked to go to a big city and enlist some samurai to help them fight off bandits who routinely steal their crops.

Film

 * Alive has two of the survivors crossing the Andes mountains in search of rescue after it's clear that no one is coming for them.
 * Seven Samurai has a couple of farmers go to a city in order to enlist help from masterless samurai. Because they're poor, the elder advises them to find "hungry samurai", and eventually they do.
 * The main struggle in My Little Pony: The Movie is the journey to Flutter Valley to petition the Flutter Ponies for aid against the Smooze.

Literature

 * In With Fire and Sword, the first book of the Sienkiewicz Trilogy, two main characters end up on a virtual suicide mission to get through enemy lines in order to summon the Polish army to help their position under siege.
 * In the Knight and Rogue Series when Michael and Fisk realize there's no way the two of them will be able to escape capture by Ceciel's guards Michael makes himself the most noticible thing imaginable after giving Fisk the orders to run for it and let someone know he's been abducted.

Video Games

 * The Elder Scrolls IV: Oblivion lets you do this in an optional quest; the city of Bruma is under attack by an enormous Oblivion Gate, and you can request help from the other cities in the province (which they'll send, but only after you close the gates threatening them, first).
 * Mass Effect 3 is pretty much Bring Help Back: The Game. You spend much of the game rallying any help you can think of and also solving several conflicts along the way to free up the conflicting parties' war resources, so you can take back Earth from the Reapers.

Real Life

 * During the siege of the Alamo, a number of couriers were sent out of the fort to bring back reinforcements. They didn't make it back in time.