Slattery struggles to evade the sub; Chandler and the land team infiltrate the immune compound; Danny discovers that Niels is working for the Ramseys; Chandler manages to encroach Sean's inner circle.

With Dr. Scott on the verge of a breakthrough, Chandler and his team set out to land in search of much needed supplies and materials for her lab. Once there, Burk stumbles upon a gang of children who have been offered a bounty by the Immunes for information on the U.S. Navy. A vicious battle ensues when the Immunes come to collect their prisoners. Back on the ship, Rachel's efforts to produce a spreadable cure depend on Niels - her success now inextricably linked to the scientist who nearly erased mankind.