After returning from the horrors of Nicaragua, panic begins to spread throughout the ship when Lt. Danny Green comes down with a mysterious illness that could be the virus. Losing faith in Rachel and her failing vaccine trials, Chandler now has to deal with a restive crew. If he fails to keep the crew together, the whole mission is in jeopardy.

The crew of Nathan James discovers that hospital ship USNS Solace was sent to sea to wait for Dr. Scott's cure. Captain Chandler sees an opportunity to add another ship to their fleet while Rachel is eager to find a lab better equipped to replicate the vaccine. When Solace fails to respond to radio communications, Chandler and his team board the ship...and come face-to-face with an unexpected enemy.