Following a shift in violent animal behavior, the team attempt to rescue Jamie and secure the leopard that could hold the key to curing the animal crisis.
Abe and the team's new member, Dariela, go to find a possible survivor of Dariela's squad. Meanwhile, Jackson and a local seek out the source of the new mutation, while in Canada Jamie tries to get back to civilization.
A series of mysterious electrical deaths in Geneva--including the team's ally, Eleanor--provide a trail to the next stage of the animals' attacks on humanity. Meanwhile, Jamie and Logan continue their trek through the wilderness.
The team flies to Vancouver to recover a sloth with the mutation, only to discover that Davies has perfected a gas to kill the mutated animals... and Jackson. Meanwhile, the men who hired Logan come looking for him and Jamie.