As the survivors prepare to escape the area by raft, Alicia turns back to save one more person trapped in the fallout.

As Morgan, Grace and Mo struggle to adapt to life on the submarine, a food shortage forces them to face the nuclear fallout outside the sub.

Against the advice of the group, Sarah searches for Wendell, and in the process encounters a dangerous survivor who forces her to take part in a search of his own.

Mortally wounded Morgan must decide whether to help a desperate stranger while a mysterious bounty hunter tries to finish what Ginny couldn’t.