Skullduggery Pleasant is a fantasy novel series written by bestselling Irish author Derek Landy. The books are themed on the adventures of a skeleton detective, named Skulduggery Pleasant and a teenage girl named Valkyrie Cain/Stephanie Edgley together with other friends.

The main plot of the entire series details the struggles of Valkyrie in trying to stop the whole world in from evil forces that threaten it, trying to get justice for the death of her uncle and the efforts to retain the darkness within.