Along the West Coast, a huge barrier has been built to prevent the penetration of hybrids into the north of America. Chloe, Jean-Michel, Jackson, and Abraham find the missing three bears in an old fortress, where the animals awaken from hibernation and attack. Tessa instead convinces Jackson to think like his dad and take another look at the encrypted code. In return, they trace Robert Oz's location in Washington, D. Elsewhere, Abigail is dragged to safety by hybrid wolves, revealing that she can control them just as Jackson controls the animals. They dig up a grave to gather the triple helix, after which Dariela decides to stay behind to escort the locals to a safe zone.
Jackson discovers through Logan that the bomber is Abigail Westbrook, his heretofore unknown biological sister. Abraham is working as a bodyguard against the animals. The team find a stockpile of the gas. Mitch splits off from the group to visit his daughter and her mother in Boston. Jamie and Mitch manage to stop the Gorilla. Abe, now a doctor, is trying to find a cure.
Mitch examines the captive bear, which apparently fell into hibernation. Abraham, Mitch, and Jamie drive Jackson to the hospital in Harare, which is being evacuated because animals are attacking. There, Abraham learns that Robert is still alive, but he decides to withhold this information from Jackson. Chloe learns that the Noah Objective will not only kill the affected animals, but will also cause over 2,000,000 human casualties. Abigail uses the plane's situation to discover the secret of how Jackson can control animals. En route, Jackson gets cornered by a tiger, but it fails to pay Jackson any attention.
A man is led into an ambush by a dog owned by a hotel. Abraham is working on a drug that would reverse the effects of gas. The series premiered on June 30, 2015, on. In Paris, the bear caught in an apartment is just one out of a sleuth of four. Later, Jackson confesses his true identity to Tessa, who leaves him.
S premiere, and was simulcast in Canada. In March, was cast in a recurring role. In April, was cast in a recurring role. She later reunites with the team. Journalist Jamie Campbell is convinced this is caused by new food that was contaminated with pesticides from Reiden Global, a biotechnology company, and starts to investigate together with veterinary pathologist Mitch Morgan. Jackson recognizes the signal pattern as a mixture of his and Abigail's brainwaves, which makes Mitch think that Jackson can safely move through the sonic barrier protecting the beacon.
Jackson begins to behave erratically by almost beating a soldier to death. There, they learn that they need to find a live sabretooth cat a species thought extinct, but actually inhabiting a Pacific island called Pangaea. As Jackson and Abraham steal the sloth, Chloe and Dariela distract the guards, causing a gas canister to explode. Before going to Zambia, Mitch needs an to examine the African animals for the mutation. Abraham is forced to reveal to Jackson that Robert is alive, and that he Abraham was likely responsible for his mother's infection years earlier. The team head off to , where a special forces team comes across a human who has mutated into a monster and who kills the team with the exception of Dariela Marzan.
In Rio, Silva holds Chloe and Mitch captive. As soon as they find the culprit, they continue to Caraquet. Overrun with hybrids, Jackson and Sam offer to lead the hybrids away and allow the others to make a run for the Barrier. Abigail is returned to her headquarters, where her fellow Shepherds revive her in another stasis chamber. While Jamie helps one Clementine, the other Clementine begins questioning Mitch.
Logan and his team find the spore nest. Back in New York, Jamie states that she did not kill Ducovny, but required Mansdale to testify for her. Meanwhile, Jamie and Logan have found that beavers have created dams large enough to divert rivers, changing the local terrain. On his way through town, Jackson is attacked and bitten by a dog. However, they arrive to find Eleanor dead in her hotel room. The remainder of the team arrives at the safe zone to find Clem's mother and stepfather dead. Jackson discovers that he has the mutated gene; he and Chloe decide to keep this development a secret.
Jamie infiltrates Reiden's Paris office to hack into their accounting records. Meanwhile Jackson has begun decoding Abigail's dead-man switch. The team is divided on the issue until Jackson, using the remote control, crashes the jet into the Barrier, saying that the new hybrid threat is a problem for another day. On the flight there, the plane is taken over by General Davies and his soldiers. Hartley makes an optometrist inject a sample of the mother cell into his eye. In this area, Jackson Oz as Dylan Green is working with Tess as a friend trying to get as many people as possible into safe zones. Abigail awakens in the operating room and stabs Abraham, grabs a gun and shoots Jamie, Mitch and Max.
Eventually, Delavenne frees Chloe and shoots Gaspard. At the Los Angeles Zoo, a lion keeper is attacked. Before her death, Chloe received a message informing her that Jamie is going to Caraquet. The dealer agrees to give it to them if they find a venomous spider. Dariela warns them the recent destruction of the hybrid nest has covered the city in toxic spores; if any of the air gets into the plane, everyone will die. Mitch, Jamie and Logan are caught by Davies. After witnessing Robert sacrifice himself to save Jackson, Abigail took over the Shepherds and saved Mitch from death.