A lot has changed. Roarhaven is now a magical city. Valkyrie has been out of action for years, recovering from the war against her alter-ego. Some things never change though: Skulduggery Pleasant is still there to stop bad people. When Skulduggery learns of a plot to resurrect a terrifying evil, he persuades Valkyrie to help. But they need someone else on their team who can go undercover. Enter the overlooked and unremarkable Omen Darkly. Between them they have 24 hours to save the world.