Mathias is under pressure. Meg Mathias, his wife, has turned up in Aberystwyth, and he's under investigation by the IPCC following the death of Mari Davies. When a bus driver's body is found shot on an isolated mountainside, the investigation provides a welcome escape for DCI Mathias.
The team have a suspect to question, but Mathias believes he is an unlikely killer. In his current state of mind, Mathias is fascinated by the lifestyle choices of ex-soldier John Bell. He also knows that he cannot avoid Meg for much longer.
