Ethan and Vanessa's stay at the cottage is interrupted when Ethan's pursuer, Warren Roper, catches up with him. They soon make short shrift of him but Victor Frankenstein arrives and they return to London to rescue him from Mrs. Poole. Inspector Rusk is waiting for Ethan, but doesn't arrest him. Sir Malcolm's friends and colleagues agree that they cannot go to Mrs. Poole's house in the night when the witches' powers are strongest and will instead go in the morning. Vanessa seemingly agrees but leaves the house on her own, intent on saving him. The others follow, but it's a full moon and Ethan loses control.
—garykmcd