Grimm S04E13 Synopsis: Trial by Fire (3/13)

A FIERY WESEN RISES IN PORTLAND –

DANIEL ROEBUCK, GIDEON EMERY, GARCELLE BEAUVAIS AND ALEXIS DENISOF GUEST STAR –

When an arson case looks to have Wesen origins, Nick (David Giuntoli) find himself reluctantly having to ask an old foe for help.

Elsewhere, Viktor (guest star Alexis Denisof) teaches Adalind (Claire Coffee) the effectiveness of well-played diplomacy.

Meanwhile, Juliette (Bitsie Tulloch) finds herself in a confrontation sooner than expected.

Russell Hornsby, Silas Weir Mitchell, Sasha Roiz, Reggie Lee and Bree Turner also star.

GRIMM -- "Trial by Fire" Episode 413 --  (Photos by: Scott Green/NBC)