Cosima examines and tests the tooth that Charlotte found in the woods from the creature. At the same time, a man at Revival in the woods by himself is spooked and then attacked by the monster.
Cosima flashes back to an intimate moment between her and Delphine, when they first found out that Cosima's DNA was intellectual property and that she was "owned."
At Revival, people panic after the man's attack. A group sets out to take care of the problem. Mud panics, insisting that he doesn't want to hurt anyone. She privately confesses to Cosima that the man wasn't always violent -- he only became that way after PT began doing new experiments on him. Mud was the one who let him out of his cage, free in the woods.
Mrs. S and Sarah finally let Kira in on a bit of what is going on and what they have been investigating.
PT gives Rachel the innoculation that Cosima made for their hereditary disease. Rachel updates him on the fact that 1300 subjects are being prepared for implantation to continue human cloning experimentation. PT tells Rachel she must visit Susan. She questions why the people at Revival are hunting the creature to capture it instead of just kill it. PT reacts defensively.
PT calls in Delphine and tells her that Cosima is meddling. She asks what information he needs.
Rachel meets privately with Susan and thinly apologizes for having tried to kill her. She threatens Susan and reminds her that PT put her in charge, at his right hand.
Delphine goes to see Cosima and explains that she was with PT. Cosima explains to her what she figured out after investigating Aisha -- that they are manipulating her tumor with gene therapy. Delphine points out that Leekie was doing the same kind of research except on skin conditions and using spiny mice.
Kira tells Sarah all about the spiny mouse. Sarah tells Kira that she went to see Helena. She asks Kira to teach her everything she knows about the feeling of connection to all the clones, in exchange for that, Sarah promises to tell Kira about all the grown-up things going on. Kira agrees.
Delphine and Cosima look at Aisha's tests, but Delphie spots the other DNA that Cosima has been examining and questions her. Cosima confesses about the man who was experimented on and is now attacking people in the woods.
One of the men on the mission to retrieve the creature tells Mud that if the creature gets too close, he will not hesitate to kill it.
Delphine warns Cosima not to keep investigating, because they are on to her and know what she's doing. Delpine tells Cosima that Rachel now hs access to Kira, and Cosima is horrified The messenger arrives to retrieve Delphine for dinner. Cosima invites her, claiming that she's found the fountain of youth PT is looking for -- Lin 28A gene.
The Messenger takes them back to the house to get dressed for dinner. Cosima and Delphine dress in a tux and old-fashioned gown, respectively, despite the Messenger's obvious displeasure.
At dinner, Cosima is surprised to see Susan and Ira there, especially that Susan is breaking bread with Rachel now. Both Susan and Ira are visibly on guard.
Cosima spars with PT over Darwin. PT asks Cosima about her parents -- a thinly veiled threat since Susan knows their names. Cosima explains that she hasn't told them anything, and that they still think she is in school in Minnesota. Rachel arrives for dinner, giving Cosima an icy reception.
Sarah and Kira bond over Sarah filling Kira in on everything that is going on.
At dinner, PT reveals that Delphine told him that Cosima went and found his secret basement. Rachel informs Delphine that her ride to Geneva is there. PT allows Cosima to see Delphine out privately. In private, Cosima confronts Delphine about having revealed to PT that she was in his basement. Delphine explains that it was to protect the endgame, and that she is going to Geneva to work with Adele and Felix on their big plan.
Mud and her companion find the creature's hideaway. The creature sneaks up and kills the man after the man tries to shoot him. He attacks Mud, but lets her go when he seems to recognize her. A while later, Mud and the man's body are found by other members of the search team.
At the now-disbanded dinner, PT and Susan explain to Cosima that the creature was their first Lin 28A experiment, and that they found him in an orphanage. The experiments did not work to bring about rapid healing, as the gene made possible in Kira.
Members of Revival arrives to inform the group that the creature has made its way to the village. Susan, Ira, and Cosima are locked away in an upstairs room. Susan confesses to Cosima that they are planning to harvest Kira's eggs to see if the trait is heritable. They are planning to put the eggs in the 1300 surrogates. Cosima is horrified, noting that these would be Kira's children and Sarah's grandchildren. She begs Susan to help her stop PT, but Susan says she can only help mitigate the damage.
Cosima goes to stop PT herself but notices that Ira is beginning to glitch on her way out. She finds Mud in the house, who tells her that the man's name is Yannis. Mud also reveals that PT is sick, and that's why all this experimentation has been going on -- to prolong his life.
Cosima ventures down into the basement where Yannis and PT are. She berates PT for having dismantled Yannis, who only wanted to return to his "home" -- the prison in PT's basement. PT points his gun at Cosima, then puts it in her hands, encouraging her to do the ethical thing and put Yannis out of his misery. Cosima refuses to give up her humanity and moves to comfort Yannis. Instead, PT brutally shoots Yannis dead.
Mrs. S, Sarah, and Kira lie together in bed sleeping. There's a knock at the door. Mrs. S goes downstairs to find Delphine, who gives her all the information she has on the Lin 28A gene they are looking to explot in Kira before she heads off to Geneva. She asks whether they can count on Siobhan's inside source, who led them to Virginia Coady. S isn't sure they should have trusted that person to begin with.
Cosima is locked in PT's basement, screaming to get out.