Sum of Existence

What would you do if you could change the past?

Liz Murphy's happy life is destroyed in one night by a vicious attack. Tormented by nightmares, she attempts suicide. Her desperate parents turn to an ambitious psychiatrist, Doctor Juliet Kin, who hypnotises Liz to help her forget what happened. The treatment appears to have worked, but the attacker is enraged that Liz can't remember him and vows to make sure she never forgets him.