West Midlands Police work to identify who is responsible for a major fire that has burned a factory in Birmingham to the ground. Fire investigator Luke Beckett is deployed to open the case before vital evidence is destroyed by the blaze, but after searching the wreckage, the cause is still a mystery. With no natural sources of ignition, Luke concludes the fire was started deliberately and, in a stroke of luck, the factory's CCTV room is left intact after the fire.