This season on Penny Dreadful, Patti LuPone (American Horror Story), who guest starred last season as the Cut-Wife, returns as a series regular in the new role of Dr. Seward, an American therapist who treats Vanessa (Eva Green) with an unconventional new approach.
Wes Studi (Hell On Wheels) joins as a series regular as Kaetenay, an intense, enigmatic Native American with a deep connection to Ethan (Josh Hartnett) who also becomes an ally to Sir Malcolm (Timothy Dalton).
The third and final season also adds Robert Louis Stevenson's Dr. Henry Jekyll (Shazad Latif).
Other guest stars include Christian Camargo (Dexter) as Dr. Alexander Sweet, a zoologist who strikes up an unlikely friendship with Vanessa; Sam Barnett (2012) as Dr. Seward's mysterious young secretary; Jessica Barden (The Outcast) as Justine, a young acolyte to Lily (Billie Piper) and Dorian Gray (Reeve Carney); and Perdita Weeks (The Tudors), as Catriona Hartdegan, a scholar with expert knowledge of the supernatural.
Simon Russell Beale returns as Dr. Ferdinand Lyle. Rory Kinnear (as The Creature) and Harry Treadaway (as Dr. Frankenstein) also star.
Penny Dreadful is a frightening psychological thriller created, written and executive produced by John Logan (Hugo, The Aviator, Gladiator) and executive produced by Logan's Desert Wolf Productions, along with Oscar winner Sam Mendes (American Beauty, Skyfall) and Pippa Harris (Revolutionary Road, Call The Midwife), both of Neal Street Productions.
Penny Dreadful is a co-production between Showtime and Sky.