The CID investigates the murder of a miner, and determine that a cop killer is behind it. Sam is unhappy with the methods adopted by the team in pursuit of an arrest. Morgan, meanwhile, makes Sam an offer that shakes his world to its foundations.
An anonymous caller reports that the IRA is to start a new bombing campaign in Manchester. Sam doesn't think the warning rings true, but the team loses faith in him and starts to target the Irish community.
Sam's mentor from 2006 arrives at the station as a young DC, and is immediately the target of racist jokes. DCI Hunt leads an investigation into a spate of armed robberies.
Sam sees the chance to prevent a murder when he comes across the younger version of a villain he will arrest in the future. But he worries that, back in 2006, Tony Crane might be released from remand and exact revenge on Sam's comatose body.