Here's the official guide of Grimm season 2 episode 18 "Ring of Fire". This episode airs on Friday, April 19 on NBC.
UPDATE: The title for this episode has been changed to "Volcanalis".
THINGS HEAT UP IN PORTLAND WHEN NICK FACES A VILLAIN UNLIKE ANY OTHER –
- Nick (David Giuntoli) finds himself fighting a wildly different sort of nature freak in a desperate attempt to keep a volcano from burying Portland in lava.
- Meanwhile a pregnant Adalind (Claire Coffee) meets a powerful new ally (guest star Shohreh Aghdashloo) in Europe.
- Meanwhile, Juliette (Bitsie Tulloch) seeks out help after becoming overwhelmed by the latest side effect of her recovery - multiple memories of Nick showing up everywhere.