The station is abuzz as Nick and Hank are called to a case where an innocent flash mob results in a gruesome homicide. As Nick delves further into the investigation, he learns more about his unique family history, and finds himself at odds when he and Hank are assigned to protect a dark character from his recent past.

When the severed head of a young man is found under a bridge, Nick and Hank find themselves on the case of Japanese Wesen acting on an ancient tradition of revenge. Elsewhere, Adalind decides to go back to work at her old law firm and has her first face-to-face with Eve.

Suffering from the bite he sustained, Sargeant Wu becomes entangled in a surprising altercation that may land him in hot water. After meeting the mysterious Bonaparte, Adalind is faced with a difficult decision that could change her and Nick's lives forever. Meanwhile, Hank gets even closer to Zuri and their relationship begins to take shape. Back at HW, Eve senses that a new force may jeopardize the entire operation.