Bryant and May on the Loose recounts the most recent events of London's Peculiar Crimes Unit. Although they are on permanent hiatus, a headless body found in the environs of the work being done in anticipation of the 2012 London Olympics sets the group back in to motion. Thinking it is the work of gangs, nobody, including the Prime Minister wants this information to get out and ruin the building and rebuilding that is going on in London's King's Cross neighbourhood.
Like all of the Bryant and May mysteries you have to love London history which plays a pivotal role in every case. And the history of this case goes all the way back to pagan times as more headless bodies turn up in the area.
John May uses his relentless logic and understanding of human nature and Arthur Bryant uses his unusual interest in history and the occult to solve the murders. The head of Homeland Security has given them four days to solve the mysteries or their permanent hiatus will become a permanent ending. Can they do it?