How do you have a premonition about something that's already happened?

Psychic P.I. Piper Ashwell has struggled with cases before because she couldn't see the future. But when she finally starts having some premonitions and they lead her to a cold case that's been unsolved for years, she really starts doubting her abilities.

Piper is convinced what she saw hasn't happened yet, and that can only mean one thing. The killer is back, and he's claimed another victim. Can Piper find the missing girl and close the cold case once and for all?