When the police are called in to investigate the death of a security guard at the local quarry, it seems that an autistic teenager's report of seeing aliens at the quarry the night before may make him a witness to the crime. Laurence Burrell is fascinated by UFOs and the like but because of his condition, is not very useful to Frost as a witness. The owner of the quarry, Charles Lightfoot, isn't very cooperative either. He's clearly been targeted by vandals causing some very expensive damage to heavy machinery but has never reported these incidents to the police claiming he doesn't want to affect his insurance rates. The area is scheduled for redevelopment as a posh housing development but Frost isn't quite sure what Lightfoot's role in all of this might be. Frost also has to deal with what appears to the parental abduction of a young lad by his father. He is pleased however that DS Hazel Wallace has returned to Denton CID, albeit temporarily, and he assigns her to investigate a series of petty robberies taking place in their area.
—garykmcd