He stripped off his skin and tossed it into the fire and he was in human form again.
Three ambitious monster hunters, Michael Patterson, Dave Gimlin, and Vera Saldona, are outside Portland, looking for Bigfoot. Michael tells Dave to do his Bigfoot call and then they find fresh kill. Something lunges out of the woods and they’re forced to run while recording everything on their cameras. One of them drops their camera, which records Michael being thrown into a tree.
Thom Carson is working at a stable and hears the horse moving nervously in the corral. He goes out and sees something attacking the horses, and opens fire. The intruder runs off and Thom calls Juliette to tell her that one of his horses has been attacked. Juliette is soon there and Thom tells her about the attack. She confirms that the attacks were made by something with a very large mouth. The rancher takes her to where the creature broke through the fence and they find unusual hairs and large human-shaped footprints. They also find traces of blood and Thom realizes that he hit the creature. They follow the tracks and find a sneaker... with a foot inside. Continuing on, Juliette finds the corpses of two of the three monster hunters.
Nick is at the trailer trying to find a match for the hidden map that Marie gave him. Juliette calls and tells him what she’s found, and Nick heads out their with the police. Hank and Nick examine the bodies and confirm that they were made by an animal even though the footprints are human. Wu finds the hunters’ camera and as they start to examine it, Vera emerges from the woods, bloody and screaming. She insists that Bigfoot attacked and killed her two friends.
Back at the station, Hank and Nick report to Renard. The footage shows something wearing clothing attacking the two hunters, meaning it’s murder. Vera is in the hospital and Nick says that they’ll talk to her in the morning.
At home, Juliette wonders to Nick what killed the hunters and he tells her that it was a human being. She isn’t convinced that it is human, pointing out that if it’s the same thing that attacked the horses then it can’t be human.
Eddie is at home sleeping when he smells something and wakes up. He goes downstairs and hears someone moving outside the kitchen window. Eddie reverts to blutbad form as the intruder enters the house. When Eddie attacks it, he’s surprised to discover that he knows the intruder: Larry McKenzie. He dumps Larry on the couch and notices that he has a gunshot wound on his leg. Larry, a wildermann, is still in beast form and tells Eddie that it isn’t working. He starts to go berserk and then passes out, and Eddie realizes he hasn’t transformed back to human form as he should.
Nick is woken with Claudia Harding with AP calls and asks for a statement about the “Bigfoot Murders.” When he arrives at the station, he discovers that reporters have gathered. The partners learn that Vera told the doctors about Bigfoot and someone leaked it to the press. Renard makes a brief non-committal statement to the reporters. Meanwhile, Eddie calls Nick and tells him that he may have Bigfoot on his couch. As Nick heads for the door, and Hank joins a search party, Wu reports that the search teams found a wallet that may belong to the killer.
Juliette calls a friend, Frank, and asks him to run a DNA test on the hairs she found.
Nick arrives at Eddie’s house as his friend binds Larry’s wound. Eddie explains that Larry hasn’t transformed back and everyone can see him as he really is. He figures that Larry is stuck halfway in-between, but insists that he’s no killer. Larry attends a wesen support group with Eddie and was seeing a therapist, Konstantin Brinkerhof, who helps wesen deal with their issues. As they talk, Eddie smells search dogs outside and they realize that the police have followed Larry’s trail. However, Eddie explains that he’s marked his territory, repelling the dogs. He then removes Larry’s shirt and puts it on against Nick’s advice, and leads the dogs off into the woods. Hank runs after the dogs and is close behind when Eddie roars at the animals, frightening them away. The detective draws his gun but Eddie jumps him, knocks him to the ground, and runs away before Hank can fire.
Eddie returns to his house and tells Nick that he ran into Hank, who saw him in his blutbad form. Larry comes out, moaning in pain, and pulls a device out of the back of his neck. He then tells them that he didn’t want to and collapses, dead. He transforms back into human form and Eddie wonders what they should do. Nick says that they have no choice but to move the body. Hank calls and tells Nick what happened, and figures it’s the killer because he was wearing the same shirt as the killer on the recording.
Nick and Eddie haul Larry’s corpse into the forest where the dogs confronted Eddie earlier. As they prepare to leave, Eddie insists that something must have been going on to drive Larry berserk, but promises to find out. As they go back to Eddie’s house, Eddie explains that Larry’s therapist, Brinkerhof, is also a wildermann.
Brinkerhof is speaking at a book signing giving a class meeting with a group and talking about facing one’s inner self as if it were a stray dog, and let the relationship unfold slowly but with love. Afterward, Nick approaches him and mentions Larry’s name. He identifies himself as a detective and briefly sees Brinkerhof’s face change. Once they’re alone, Nick asks him as a Grimm what he can tell him about Larry, warning that he won’t let Brinkerhof hide between doctor-patient confidentiality. Brinkerhof admits that Larry is suffering from impulse control but nothing unusual for wildermenn. He tells Nick that Larry was making progress but there was no fast route. Hank calls Nick to tell him that they found the killer, dead in the forest. As Nick leaves, Brinkerhof suggests they talk about his dual identifies as Grimm and cop sometimes, warning that eventually the inner man comes to the fore.
Juliette examines the hair samples at the lab and concludes that it’s hominid, possibly primate.
Nick meets Hank in the forest as his partner remembers Eddie’s near-attack on him and is sure Larry looked different. One of the techs confirms that the device is a drug delivery implant. It has a serial number and Nick tells him to take it to the lab to find out what’s in it. Renard is nearby giving a press statement closing the case now that Larry is dead.
That night, two homeless men are camped out in the woods near a water tower. One of them, Wallace, goes into the woods to relieve himself and a hominid attacks him. It charges out of the woods and attacks the second man, Harold, who impales his attacker by accident with a board and runs off. The next morning, Nick and Hank are called in and talk to the witness. They then check the body and confirm it’s in the same condition as Larry’s when he died. Wu checks his license and confirms that the killer is Alan Evercroft, a lawyer with a family of three. Nick notices an implant in his neck just like the one that Larry had.
Juliette’s friend Frank calls her back to tell her the DNA test is inconclusive. It appears that the hairs came from a creature with two different genetic structures. He sends the test results to Juliette and she starts doing research on parahuman half-human/half-animal genetic mixtures.
Eddie goes to the bar where he met with Larry and the others. The owner, Reynaldo, is also a wesen and admits that the last time he saw Larry was three months ago. Larry came in and said that he was cured. He claimed that he had a foolproof overnight cure but wouldn’t say what it was. Several other wesen, including Evercroft, all went to see Brinkerhof and then disappeared.
The technician informs Nick and Hank that the drug was a combination of steroids and herbs. They’re waiting for a call back from the company that manufactured and sold the pump. Eddie calls Nick and tells him about Evercroft and the third wesen, Dan Murray., who went to Brinkerhof for a quick cure. Nick tells him that Evercroft was killed the previous night and had the same pump in his body. Eddie tells his friend about the cure and offers to call Murray, and Nick warns him that they haven’t tied anything to Brinkerhof yet.
Eddie calls Murray and gets his brother Travis. Travis tells him that Dan died two days ago as he looks around the apartment that Murray tore up before climbing out the window and falling to his death.
Hank runs a check on Murray and comes up with the news of his death. The local police ruled it a suicide but they found a drug pump in his neck. Wu reports that Brinkerhof ordered four of the pumps, and they’ve accounted for three. Renard tells them to find out who has the fourth pump.
Brinkerhof is at his office writing and starts to lose control. Eddie knocks at the door and hears Brinkerhof growling briefly. The psychiatrist gets control of himself and answers the door, and finds Eddie there. Brinkerhof tells him to leave but Eddie demands an explanation for why his friends are dead. The psychiatrist says that his three patients wanted to give up control so that they could have freedom, and admits that he didn’t test the drugs before administering them. Brinkerhof starts to lose control and prepares another dose, but drops the bottle and begs Eddie to help. However, he loses control, reverts into his full wildermann form, and lashes out at Eddie. Eddie transforms into his blutbad form and fights back, but Brinkerhof throws him aside. Nick and Hank arrive and Brinkerhof leaps out the window and runs away, while Eddie reverts to human form before Hank can see him. As they go, Hank wonders why Eddie is there and Nick says he’s a patient.
Brinkerhoff runs through the streets, attacking two men. One of them runs off and calls the police. He then smashes his way into a theater reception and the crowd runs in terror. Brinkerhof knocks out one woman and drags them away. Hank and Nick arrive seconds later and the manager tells them what happened. The police move into the theater and spot Brinkerhof, carrying the unconscious woman. The officers go up into the catwalks and Nick finds the woman, unconscious but alive. Brinkerhof sneaks up on him and Hank arrives just in time to shoot him. The psychiatrist falls into the seats below and Nick and Hank run down. As Hank watches in astonishment, Brinkerhof transforms to human form upon his death. Nick claims he didn’t see anything but Hank starts to crack up trying to reconcile what he saw.
Later, Eddie meets Reynaldo and they share a toast to their departed friends. They listen to a news report about Brinkerhof’s death, dismissing the reports of Bigfoot as mass hysteria and claiming Brinkerhof wore a Bigfoot mask.
At home, Juliette tells Nick that she analyzed the hair samples and confirmed that they couldn’t be matched to any known species. Nick suggests that the tests were wrong, but Juliette wonders if there are real creatures out there.