The Darkness Outside Us by Eliot Schrefer

Two boys, alone in space. Sworn enemies sent on the same rescue mission.

Ambrose wakes up on the Coordinated Endeavor with no memory of a launch. There's more that doesn't add up: evidence indicates strangers have been on board, the ship's operating system is voiced by his mother, and his handsome, brooding shipmate has barricaded himself away. But nothing will stop Ambrose from making his mission succeed--not when he's rescuing his own sister.

In order to survive the ship's secrets, Ambrose and Kodiak will need to work together and learn to trust each other . . . especially once they discover what they are truly up against. Love might be the only way to survive.