Mr. McGuire takes Maggie, Raphael, Fiona, and Hasenpfeffer to Scotland to meet one of his oldest friends, Sir Roderick Lachlan, who will conduct Maggie's World Federation of Magic testing. Also at the estate are smarmy young house guest—Munro Wallace Shaw, his mentor—Lord Gilroy Innis, Sir Lachlan's wife, Lyra, a depressed selkie who endlessly searches the castle for her hidden seal skin so she can escape back to the sea, and their daughter Rhona—a troubled child at odds with her selkie heritage. When a panther attacks their host, Maggie and friends must figure out who conjured the creature up and why. Add a sneaky black cat, Maggie and Fiona's troublesome attraction to Munro, and Raphael's jealousy to the mix, and the next victim might very well be Maggie.