The dark is rising... Detective Inspector James Quill is about to complete the drugs bust of his career. Then his prize suspect Rob Toshack is murdered in custody. Furious, Quill pursues the investigation, co-opting intelligence analyst Lisa Ross and undercover cops Costain and Sefton. But nothing about Toshack's murder is normal.

Toshack had struck a bargain with a vindictive entity, whose occult powers kept Toshack one step ahead of the law – until his luck ran out. Now, the team must find a "suspect" who can bend space and time and alter memory itself. And they will kill again.

As the group starts to see London's sinister magic for themselves, they have two choices: panic or use their new abilities. Then they must hunt a terrifying supernatural force the only way they know how: using police methods, equipment and tactics. But they must all learn the rules of this new game – and quickly. More than their lives will depend on it.