York, 1865. An explosion tears through the brake van of a passenger train waiting to depart, and guard Jack Follis emerges fatally burned. The North Eastern Railway summons Colbeck and Leeming to determine whether the blast was an accident, vandalism or a carefully targeted killing.
The inquiry spreads through York’s railway community and an archaeological excavation that has awakened old rivalries. With conflicting motives and evidence concealed by the violence of the explosion, the detectives must reconstruct Follis’s final movements before the killer can exploit the confusion again.