You're the One That I Haunt
Being Human Season 1 Episode 12 (04/04/11)
Sally is damaged after the exorcism, and only attempting to slit his throat brings her back to "life."
Josh and Aidan try to cope with Sally's changes and the possibility that Bishop will kill them at any moment.
We learn who Celine is! After all the years apart, when Aidan learns she is dying he offers to turn her. She refuses the offer, but he finally gets closure on his relationship with her.
Nora is concerned about her pregnancy. High HCG levels indicate a possible problem and she seems to be moving through pregnancy at an accelerated rate. They find out the baby, although growing rapidly, is healthy.
Sally's haunting ends her journey with Danny. Her door finally appears.
As Sally contemplates going through her door, Bishop jumps through the window and stakes Aidan. Aidan bleeds, and doesn't turn to dust. The door remains.