Hart and Cohle get a new lead in their 17-year-old case.
Hart and Cohle investigate a string of disappearances that may be tied to the Dora Lange murder and the Tuttle family.
When a cargo ship washes ashore in Massachusetts, a terrifying rat infestation is revealed; Mitch gets ready to make a trade in order to save his terminally ill daughter.
The team comes together on the island of Pangaea to put the final pieces of the cure in place.
Jamie tries to expose Reiden's involvement in the global animal problem; Mitch escapes; Mitch and Abraham run into an army of birds.