It's a defiant hobby with dangerous consequences, which Kell is now seeing firsthand.After an exchange goes awry, Kell escapes to Grey London and runs into Delilah Bard, a cut-purse with lofty aspirations. She first robs him, then saves him from a deadly enemy, and finally forces Kell to spirit her to another world for a proper adventure.Now perilous magic is afoot, and treachery lurks at every turn. To save all of the worlds, they'll first need to stay alive.