Jackson, Jamie, and Chloe travel to Mississippi to investigate the prison fire, while Abraham and Mitch go north to trap and study wolves.

Jackson, Jamie and Agent Shaffer search for a chemist in Alabama who has evidence of Reiden Global's role in the growing animal problem. Meanwhile, Chloe, Mitch and Abraham fly to Rio de Janeiro to delay the local government's plan for a massive bat extermination and come up against a ruthless drug lord.

Abraham works to save Chloe and Mitch from a drug lord; Jackson and Jamie continue to work with Agent Shaffer in search of Evan Lee Hartley and the Mother Cell after Leo is killed in the crash.

The team discovers a terrifying rat infestation when a cargo ship carrying the bloodthirsty rodents washes up off the coast of Massachusetts. Also, unbeknownst to the rest of the team, Mitch reconnects with his terminally ill daughter in Boston as he prepares to make a trade with Reiden-Global to save her life.