The crew of a lone naval ship try to save humanity when they discover a deadly virus has wiped out most of the population in the series premiere of this drama.

The crew members arrive at the Guantanamo Bay military base to collect food, fuel and medical supplies. When they come under attack by escaped Gitmo prisoners.

The crew faces a new foe targeting Rachel and her research, leading Chandler to engage in a series of dangerous strategic maneuvers.

Chandler's leadership is put to the test when the ship's propulsion system is in danger of breaking down, the crew becomes overworked and exhausted.

A mission to help Rachel with her vaccine trials leads Chandler and a small team into the jungles of Nicaragua.

Panic spreads when Danny Green catches a mysterious illness that might be the virus. Doubts rise about Rachel and her failing vaccine trials as Chandler deals with a crew whose uneasy state grows.