Sebastián, a psychology student, is accused by his faculty of causing his ex-girlfriend's suicide. While trying to prove his innocence, a deep sense of guilt consumes him and prevents him from defending himself.

Elisa, a lonely and shy librarian, moves to live in a downtown building, without knowing the killing of a young student took place there some time ago. A strange feeling taking over her will cause a drastic personality change while also leading her to unveil the secret behind the murder.