Nick and Hank search for a murderer who kills their victims with a highly corrosive poison. At the first crime scene, the only clue found is a finger, bitten off of the murderer's hand. Nick discusses his exposure as a Grimm with Monroe who says that the Wessen, those of the creature world, are just curious about him. A second murder brings Nick to question Monroe about them. Monroe reveals the killer to be a Spinnetod, a spider-like creature. Nick goes to the home of the Eisbiber who have been bothering him and tells them he won't hurt them and to stop spreading rumors about him. Monroe and Nick visit a Spinnetod friend of Monroe's who tells them all about Spinnetods. She says they have to eat three young men every five years within a small period of time to avoid aging rapidly. Lena (Amy Acker), the Spinnetod, is caught while trying to kill her final victim. Nick and Hank pick up Lena's daughter to take her to extended family and Nick sees her morph into a Spinnetod, afraid of the cycle that will repeat eventually, though he says nothing. Finally, Lena is seen sitting in a jail cell aging rapidly.