Code 404

Major and Carver reunite, but tensions remain high; when a police officer is murdered, Carver becomes hell-bent on solving the case; Major has an epiphany and resolves to become a better man; both detective inspectors are out to prove themselves.

With a serial killer at large, Major and Carver seek the help of a forensic psychologist, Professor Sarah McAllister; Parfit is concerned about the results of Major's A.I. updates.

As the body count rises, Carver and McAllister have no choice but to follow the clues and play the killer's twisted game; Major becomes increasingly disillusioned as he deals with Carver's rejection and an outside threat to his A.I.

Major starts to fall apart under the pressure of a compromised A.I., explosive secrets and Parfit kicking him out of the lab; a witness provides a shocking revelation, leading to a breakthrough in the serial killer case.

Chalmers, the former police commissioner who has plagued Major since the day he was reanimated, faces trial; with Major busy testifying, Carver's running out of time to decipher the latest clue and save the killer's next target.

With time running out and suspicions running wild within SIU, Carver must clear Major's name and thwart the killer's final revenge.