DI Nancy Ravenscroft is thrust back to work with a puzzling murder case: a body discovered in the middle of the night at an unusual dump site. She quickly realises this victim is the first of many, and she's not convinced they've been selected at random.

Could her team be dealing with a copycat killer taking inspiration from a local true-crime podcast? And could the culprit be hiding in the comments of the podcast's fan forum? Needing someone who can spot an imposter amongst the genuine voices, Nancy brings in forensic linguistics expert Professor Ewan Laing.

Ewan's insight immediately sheds new light on the evidence. But as the pair wade through conflicting and missing leads, are they chasing ghosts, or getting close to exposing an imposter with a growing audience and a taste for murder?