Nathan James returns home to Norfolk on a mission. With his family now safely aboard the James, Chandler sends his crew in search of their friends and loved ones.

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.

Chandler tracks a new threat to Northern Florida. Meanwhile, Rachel comes across a secret formula that her mentor, Dr. Hunter, had been perfecting.

While XO Slattery struggles to evade a submarine, Chandler and his team infiltrate a compound on land.

With their mission now fully dedicated to spreading the cure, Nathan James puts a call out to civilians to meet at pre-selected ports across the country.