Broadway great and “American Horror Story: Coven” alum Patti LuPone will soon be casting a spell on Showtime’s supernatural period drama “Penny Dreadful,” Variety has learned.

The stage legend will guest star on the second season as a mysterious character of great importance to Eva Green’s bewitched character Vanessa.

She joins fellow new cast members Douglas Hodge, Sarah Greene and Jonny Beauchamp. Hodge will play an intense Scotland Yard investigator named Bartholomew Rusk who is on the hunt to discover who is responsible for the terrible murders that have been plaguing London. Greene will play Hecate, the powerful daughter of Helen McCrory’s Evelyn Poole, and Beauchamp has the vague and mysterious character description of a “young man with a singular past.”

Showtime has also confirmed that McCrory and Simon Russell Beale have been upped to series regulars for the sophomore season.

Production on the upcoming 10 episodes — all written by John Logan — will begin in September in Dublin, Ireland for a 2015 debut on the network.

“Penny Dreadful” is executive produced by Logan’s Desert Wolf Productions, along with Sam Mendes and Pippa Harris of Neal Street. The cast includes Josh Hartnett, Timothy Dalton, and Green. Reeve Carney, Rory Kinnear, Billie Piper, Danny Sapani and Harry Treadaway also star.