Several fatal air collisions have occured within a few months in rural Wales. According to the local Air Accidents Investigation Branch (AAIB) inspector, it's a coincidence. Clusters happen. Except, this cluster is different. DI Yvonne Giles suspects it when she hears some of the witness statements but, when an AAIB inspector is found dead under a bridge, she knows it.
Something is way off. Yvonne is determined to get to the bottom of the mystery, but exactly how far down the treacherous rabbit hole is she prepared to go?