When fire engulfs Meg's house, killing her parents and destroying her fortune and future, all she has left is the tarnished pocket watch she rescued from the ashes. But this is no ordinary watch. The watch turns out to be a mechanical key—a key that only Meg can use—unlocking a series of deadly secrets and twisted clues that Meg is forced to follow. Along with a handsome groom she barely knows but hopes she can trust, Meg dives into the hidden a world of deceit, betrayal and revenge, exposing the existence of an elite secret society and a dangerous invention that some will stop at nothing to protect.