A trio of ghost hunters go to an empty house that was the scene of a double murder years before. One of them is attacked and burned to a crisp in the same manner as the original two victims.
Renard agrees to help Juliette with her Hexenbiest problem, putting Juliette in contact with Henrietta, a venerable Hexenbiest who is an old friend of Renard's mother Elizabeth. Juliette's growing powers are becoming dangerous, and she fears what Nick will do if he discovers that she has become a Hexenbiest.
Nick, Hank, and Wu investigate the ghost hunter's death at the haunted house and decide to look into the old murder. The lead suspect for that murder hadn't been seen since the incident. After recovered camera footage indicates a possible Wesen, they go talk to the suspect's wife, who identifies the electrical Wesen as not her husband but one of the presumed murder victims, Stetson Donovan, who had walked in on his wife in bed with Theo Hinkley and killed them both in a fit of rage.
The cops find a counter to Stetson's electrical powers and hurry back to the Donovan house. Lily Hinkley has returned to kill Stetson, who is now a delusional homeless man. Nick confronts Stetson, and Lily fatally shoots Stetson despite Nick's attempt to arrest him.
Captain Renard has mysterious, unexplained bleeding that quickly vanishes where he was shot by the Hundjager FBI agent at the end of last season.