Crysis Legion tar fatt på historien etter Crysis 2, der Alcatraz gjenforteller hendelsene i Crysis 2 fra en helt ny vinkel.

 

Fra baksiden av boka:

 

"Welcome to the Big Apple, son. Welcome to the city that never sleeps: invaded by monstrous fusions of meat and machinery, defended by a private army that makes Blackwater look like the Red Cross, ravaged by a disfiguring plague that gifts its victims with religious rapture while it eats them alive. You've been thrown into the meat grinder without warning, without preparation, without a clue.

 

Your whole squad was mowed down the moment they stepped onto the battlefield. And the chorus of voices whispering in your head keeps saying that all of this is on you: that you and you alone might be able to turn the whole thing around if you only knew what the hell was going on.

 

You'd like to help. Reall you would. But it's not just the aliens that are gunning for you. Your own kind hunts you as a traitor, and your job might be a bit easier if you didn't have the sneaking suspiucion they could be right..."