Tom Chandler has given up his heroic titles and responsibilities and sought solace and anonymity with his family in a small fishing village in Greece. Meanwhile, Captain Slattery and the crew of Nathan James have discovered that the virus has "jumped kingdoms" and now infects the world's food crops, bringing humanity to famine.
In the season four premiere, the Nathan James faces another global disaster 16 months after thwarting the coup in America. But where in the world is Tom Chandler?
Chandler immerses himself in a mission for revenge. Meanwhile, the crew of Nathan James, having lost their only lead, continues their search for an item that could save the world.
The crew of the Nathan James searches for a precious item, leading them to a strange place of opulence and violence where they cross paths with a most unexpected ally.
As enemies close in on all sides, the crew searches for one of their own. Meanwhile, Slattery is haunted by visions of the past.
The Nathan James is diverted from their mission when they receive a suspicious distress call from a fishing trawler.
With an enormous storm on the horizon, the Nathan James must navigate an equally terrifying threat in order to make it to safety.
The search continues with a reconnaissance mission, but things turn violent when an old foe resurfaces.
An undercover mission in the land of the dead leads to disturbing revelations about the sinister plans of Dr. Vellek (guest star PETER WELLER).
The crew of the Nathan James faces a threat that will test the limits of their Naval tactics and strategies.
In the season finale, Chandler confronts his enemy – and his personal demons – in a final showdown… with the fate of humanity on the line.