Season 1 Episode 20: Spitalfields

"In 1811, QIA Agent Sarah Cunnington came into contact with Mary Bowman, a patient in Bethlem Hospital, and caused an unprecedented Paradox Event that gave Mary frightening powers. After finally overpowering her, the team brought Mary back to the twenty-first century where she has remained in a coma ever since. Now Mary has awoken, and she’s full of rage, and Sarah’s past, present and future are all about to collide…"