Welcome to Grey London, dirty and boring, without any magic, with one mad King - George III. Then there is Red London, a city slowly being drained through magical war, down to its very last bones. And once upon a time, there was Black London… but no one speaks of that now.
Offically, Kel is one of the last Antari magicians with a rare converted ability to travel between parallel Londons and acts as an ambassador and messenger between the Londons, in service of the Maresh Empire. Unofficially, he’s also a smuggler, which is a dangerous hobby for him to have - as proved when Kell stumbles into a setup with a forbidden token from Black London.
Fleeing into Grey London, Kell runs afoul of Delilah Bard, a cutpurse with lofty aspirations, who first robs him, then saved him from a dangerous enemy, and then forced Kell to sprint her to another world for a proper adventure.
BUT perilous magic is afoot, and treachery lurks at every turn. To save all of the worlds, they’ll first need to stay alive.