When a man is found unconscious and bloody in the middle of the road, Nick (David Giuntoli) and Hank (Russell Hornsby) are the men for the job. The victim, Doyle Baske, says he was on his way to his mom's house when he crashed his car. After taking off down the road, he was attacked by a man and his dog. Unfortunately for Doyle, the wounds on his body don't match his story. Suspecting Wesen involvement, Nick and Hank turn to Monroe (Silas Weir Mitchell), who sniffs Doyle's shirt and follows his scent to the site of... two dead bodies, a pair of hikers. But there's something else mixed with the smell of death. And when Rosalee (Bree Turner) reminds Monroe it's a full moon, he realizes what they're dealing with: a Lycanthrope. The inspiration for the werewolf myth, Lycanthropes are infected Blutbaden, the result of a genetic mutation. During the three nights of the full moon, they are driven temporarily insane.
To discern if Doyle is the Lycanthrope, Nick and Hank decide to hold him overnight at the precinct, only their plan is thwarted when Doyle is bailed out. Desperate to stop him from killing again, Nick, Hank, Monroe, Rosalee and Wu (Reggie Lee) corner him at the precinct. He Woges into a completely healthy Blutbad and Nick realizes the truth: Doyle's mom is the Lycanthrope. The group rushes over to her home, but they're too late; she's broken free of her restraints. While they search for her in the forest, Eliza Baske attacks Wu, who barely gets away before Doyle intervenes. He promises he can calm her down, but when Eliza moves to attack her son, she's shot dead. That night, when Wu goes home, he realizes Eliza managed to scratch him. Could the gang be battling a were-Wu soon?