Detective Chief Superintendent Frankie Sheehan does not wish to linger on the grisly scene before her eyes. Two mutilated corpses. In a church. In Clontarf. Her profiling background screams one fact: this is just the beginning of a sickening message. Meanwhile, a 17-year-old case is playing out on a TV documentary, the convicted professing his innocence and historical police errors being exposed daily in the media. Irish crime - for fans of Tana French.