At a squalid flat near the Cardiff docks, an early-morning drugs raid goes catastrophically wrong. A plain-clothes officer is shot dead at point blank range, the dealer is left in a coma. The killer, identity unknown, slips away.

Young and inexperienced, Will MacReady starts his first day on the CID. With the city in shock and the entire force reeling, he is desperate to help - but unearths truths that lead the team down an increasingly dark path …