CSI meets Harry Potter in this fantastic new graphic novel from Ben Aaronovitch, writer of the bestselling Rivers of London supernatural police procedural crime novel series!Something dark and slimy is dripping through the walls of suburban London. Not the usual stuff that smells funny and can be hell on the lungs, this mould is possessed by some dark power full of bad intentions. Looks like it's another case for London's one and only trainee wizard cop, Police Constable Peter Grant, and his reluctant partner, Sahra Guleed!An all-new adventure for Ben Aaronvitch's laconic, way-past-cool but slightly geeky trainee wizard and budding detective, Peter Grant!Tying directly into the Rivers of London continuity, set between Foxglove Summer and The Hanging TreeAaronovitch is joined by Doctor Who writer Andrew Cartmel for this gripping new series.