On the edge of a playing field in the Lancashire town of Longridge is an
abandoned railway tunnel that is reputedly haunted. It used to serve an
old stone quarry that has now been given a new lease of life as a
holiday park. Six eighteen-year-old friends are staying in a static
caravan at the park when one night a violent storm forces them to stay
indoors. One of the girls downloads a talking Ouija Board app to her
laptop for 'a bit of fun', but the following morning the three boys in
the group have gone missing. Detective Sergeant Pauline Pilkington is
handed the job of finding out what has happened to them but has little
luck until DCI Stone calls in the Unusual Investigations team of former
Detective Constable Jerry Ratcliffe and his partner, the corporeal
spirit of murdered witch Kat Hewitt. Their enquires lead them to an
encounter with a boggart known as The Headless Woman of Longridge. Then
Sergeant Pilkington disappears as well.