India and Matt thought all their problems would come to an end once they found Chronos. But the watch magician brings with him as many questions as answers, and a load of trouble. To fix Matt's magic watch, they must find an old diary that once belonged to a doctor magician murdered decades ago. The hunt drags them into a sordid mystery involving two of London's craft guilds. With old and new enemies determined to stop them, and long-held secrets...