The Exceptionals by iwillpaintasongforlou (12k)

The world has been decimated by a nuclear apocalypse. Harry lost his family and the love of his life, and is left with a nasty scar across his face and the mutated ability to heal people with his hands. When raiders come into his village trying to kidnap Exceptionals like him, Harry is forced to flee to people and places he's never seen before-- and maybe find a piece of his past in the process.

Converging Fates by ForeverRememberLarryStylinson (83k)

The one where the world has mutated and become far more vicious, harsh, and deadly than ever before. It's a survival of the fittest world, and only those whom are able to conceive children are kept to live. Most who aren't, are left out to die.

Louis Tomlinson can conceive.

Harry Styles is the leader of a cult.

Together, there is fire.

When the World Comes Down by blue_marauder (6k)

"I wouldn't breathe the same air as him even if we were the only two people on earth"

Harry didn't mean that literally. Not until Harry and Louis are the only two people alive on this earth (to their knowledge).

After Our End by missberrycake (23k)

He is a wise man who does not grieve for the things which he has not, but rejoices for those which he has. Epictetus AD 55 – 135

‘Apocalypse’ unleashes Derren Brown’s most daring plan for a television show yet – to convince internationally renowned boy band One Direction that the country has been overcome by a cataclysmic asteroid strike, that deadly infected now walk the earth and that they are a few of the mere handful of survivors.

In which One Direction have a colossal, apocalyptic trick played on them. It brings their world to a temporary end. Literally.

whispering of fields half-sown by Eliane (7k)

"And how ironic is it that even now, at the end of all things, Louis’ mere presence makes Harry want to believe that anything is possible again. That the earth isn’t close to collapsing on itself, that the tomorrows are bright and shining and full of promises. Harry hates Louis for giving him something to look forward to when the sky only keeps getting darker. Harry loves Louis for it. "

[All of his boys come back to him in the end, but it’s Louis, Harry has been waiting for all this time.]

Time Is All We Have by evelynegrey, fortunefavorsthebrave (20k)

"Okay, here's the deal," the man who'd met him outside started, "if you fuck up, or try to sell us out, or use us as bait, you're out. Okay?" Harry nodded quickly. "And we will outsmart you," he continued. "We will outrun you, so don't even think about trying." "I don't want any trouble," Harry told him, cowering slightly. "Good." He tossed him his gun and Harry caught it clumsily. "We're gonna have to teach him to shoot."

AU where the world has gone to shit, Harry has accidentally survived, Niall likes root vegetables and no one knows anything about Louis except that they would follow him to the end of the world and back. Zayn and Liam are also there.

the riotous failure of our theories by Eliane (4k)

After the world has ended there's still, etched on Louis' skin, a compass pointing to home.

bruises on your thighs (like my fingerprints) by ariadne_odair (2k)