"A Darker Shade of Magic" is a fantasy novel by V.E. Schwab, set in a universe with parallel Londons: Red London, Grey London, White London, and Black London. Each London has varying levels of magic, with Red London being the most magical and Black London being consumed by it. The story follows Kell, a magician known as an Antari, who can travel between these worlds. Kell becomes embroiled in a dangerous adventure when he smuggles a dangerous artifact from Black London. Along the way, he meets Lila Bard, a clever thief from Grey London, and together they face powerful enemies and uncover dark secrets that threaten all the Londons.