Cab driver Francis 'Chas' Chandler leads an unremarkable existence. His greatest moments have come tagging along with John Constantine -- as a chauffeur. His home life is nothing special, and his beloved London is becoming a soulless metropolis. In middle age, Chas is stuck in a rut.

But Chas is a master of 'The Knowledge,' the elaborate system of routes and landmarks which every London cabbie must memorize. Until now, The Knowledge has been just a tool for Chas. But now, he's about to discover a more sinister significance of The Knowledge.

An ominous entity from London's grim history has reemerged, and only someone with The Knowledge can stop it. Is Chas up to the task, on his own?

From the feverish mind of Simon Oliver (THE EXTERMINATORS, GEN 13) with lush artwork by Goran Sudzuka (Y: THE LAST MAN, LADY CONSTANTINE), THE KNOWLEDGE is Chas's chance to make his own mark on the dark universe of HELLBLAZER.