"A Darker Shade of Magic" centers on Kell, a magician who has the ability to travel between parallel universes connected by one magical city, in this case London. Kell can travel between four parallel worlds within London, including Grey London, where residents believe magic is a myth, Red London (where magic is revered), White London (where magic is battled over) and the dark Black London, where magic has overpowered the people. When Kell meets Delilah Bard, a London pickpocket, he's whisked into a universe-hopping adventure.