Capt. Tom Chandler and his crew set out for the Arctic with two virologists; Chandler discovers that the virologists are collecting samples of the source of a virus that has wiped out more than half of the human population while he has been at sea.
The ship's propulsion system suffers a catastrophic event; Chandler's leadership and ingenuity are put to the test.
Chandler and his crew head to the U.S. military base in Guantanamo Bay in search of food, medical supplies and fuel; escaped prisoners attack the search teams; the teams enlist the help of a private contractor.
Chandler and his crew face off against a nuclear-powered submarine led by rogue British naval officers; Slattery interrogates a captured mercenary to gain information about the sub and its mission.
Slattery must step into the role of commanding officer; Slattery must find a way to get his people back without losing the vaccine prototype.