A killer announces his next victim through graffiti, targeting the innocent in Edinburgh. D.I. Ava Turner and D.I. Luc Callanach are faced with two brutal murders: a charity worker sliced at a music festival and a teacher found strangled in an alley. With no immediate leads, they discover a chilling pattern: cryptic words appear on city buildings, describing the victims. The true horror dawns when they realize the killer is not commemorating past crimes, but preemptively declaring his future targets, with a preference for the most innocent souls.

The DI Callanach series is lauded for its gripping plots and the compelling partnership between its lead detectives. Readers and critics frequently praise Helen Fields' ability to craft suspenseful narratives that keep them guessing until the very end. The series is noted for its atmospheric settings, particularly the dark underbelly of Edinburgh, and its exploration of complex criminal psychology. This installment is expected to continue the high standard set by previous books, offering a dark and intricate mystery.