John is in mortal danger from an unexploded German bomb, but no sooner he escapes from that he is identified as a magic person by a gypsy. She, in turn, foretells that his cousin Sybil is in mortal danger herself and the price of the cure is that the two of them must travel back to the time of Empress Theresa, Holy Roman Empress. Sybil task is to save her own life as well as help lift a gypsy curse. John gains more magic from the Old Ones but is put in danger himself as he and Sybil battle against, warlocks, Danube rapids, jealous princesses and assassins.