NBC has released the synopsis for episode #517 of Grimm, which you can check out below. The installment, titled “Inugami,” is officially described as follows:
AN ANCIENT CODE OF VENGENCE PUTS THE LIVE OF LOCAL YOUTHS IN DANGER – KEIKO AGENA AND CARY-HIROYUKI TAGAWA GUEST STAR – When the severed head of a young man is found under a bridge, Nick (David Giuntoli) and Hank (Russell Hornsby) find themselves on the case of Japanese Wesen acting on an ancient tradition of revenge. Elsewhere, Adalind (Claire Coffee) decides to go back to work at her old law firm and has her first face-to-face with Eve (Bitsie Tulloch). Silas Weir Mitchell, Sasha Roiz, Reggie Lee and Bree Turner also star.
Grimm “Inugami” airs Friday, April 15, at 9pm on NBC.