Vanessa and Ethan learn that Sir Malcolm is in danger. Desperate to save him, Vanessa goes alone to battle Evelyn, while Ethan, Frankenstein, Sembene and Lyle head to Evelyn's mansion. Plus, Lily reveals her true self to Dorian.
Still hiding in the Cut Wife's cottage, Vanessa and Ethan are discovered by Roper, the bounty hunter that Ethan had mauled. Vanessa stabs him to death and they bury the body. Victor arrives to inform them of Malcolm's situation and they return home. In addition, Victor's addiction to narcotics has grown uncontrollable, and in talking to Vanessa, demonstrates his inner angst. Ironically, Caliban reflects similar suffering while talking to Putney. Later, the Putneys trap him in a cell, telling him they plan to put him on display as a "freak" in their new business venture.
The ghosts of Malcolm's family continue to haunt and torture him. While listening to Malcolm's screams from below, Evelyn prepares for Vanessa's arrival.
Lyle admits his involvement in the situation as they plan, but Ethan discourages Vanessa from attempting a rescue at night, knowing that he will change into the wolf. Sembene tells Ethan the marks on his face were indicative of his former profession as a slave trader. Hecate appears in Ethan's room and asks to ally with him. Vanessa sneaks out of the mansion to fight Evelyn on her own. Sembene, Lyle, Victor, and Ethan follow. While trapped in a stairwell, Ethan changes, and despite his anguish and resistance do so, kills Sembene. Victor becomes trapped with a clearly tormented Malcolm, and is forced to face his creations.
Lily and Dorian continue to spend time together and finally become intimate. Dorian acknowledges Lily as formerly being Brona, of which she does not argue. They agree to become partners in Lily's plan for the future as he demonstrates his power of immortality.
- Eva Green as Vanessa Ives
- Josh Hartnett as Ethan Chandler
- Timothy Dalton as Sir Malcolm Murray
- Harry Treadaway as Victor Frankenstein
- Rory Kinnear as the Creature
- Billie Piper as Lily
- Reeve Carney as Dorian Gray
- Danny Sapani as Sembene
- Simon Russell Beale as Ferdinand Lyle
- Helen McCrory as Evelyn Poole
- Douglas Hodge as Bartholomew Rusk
- Sarah Greene as Hecate Poole
- David Haig as Oscar Putney
- Stephen Lord as Warren Roper
- Olivia Llewellyn as Mina Murray
- Alex Price as Proteus
- Ruth Gemmell as Octavia Putney
- Tamsin Topolski as Lavinia Putney
- Noni Stapleton as Gladys Murray
- Graham Butler as Peter Murray
- Jack Hickey as Junior Inspector
- Nicole O'Neill as Witch #1
- Olivia Chenery as Witch #2