Major, Carver and Kelly have gone their separate ways. Things are looking up for the AI-enhanced Major, whilst Carver isballoonning for a promotion and is knee deep in a new case.

Carver and Major receive new information on the Chelsea Bridge Case - a £50 million robbery committed twenty years ago by a gang who seemed to vanish into thin air.

DCS Dennett officially reopens the Chelsea Bridge case, reuniting Major with his absent father, Clifford, who failed to solve the case 20 years earlier. As Major's AI becomes increasingly unstable, Dr. Parfit and Carver clash over the solution.

After narrowly foiling a bomb plot, Carver and Major suspect it was just one member of a much larger organisation. Clifford Major continues to throw wrenches into the Chelsea Bridge case.

Major's mood swings are getting out of hand. He and Carver are given the task of supplying Cleasby with a new identity under witness protection.

On the verge of full-blown systems failure, Major makes a desperate, last ditch effort to clear his dad's name. Carver believes he's got Clifford trapped, but the old cop isn't going down that easily.