But Merry's best friend, Teddy, is joining the Toadmen - a secret society upholding backward thinking and suspiciously supernatural traditions - and she is determined to stop him. Even if it means teaming up with her academic arch-nemesis, Caraway Boswell, an ice-cold snob who hides his true face behind a glamour.

An ancient Toad ritual is being held in the nightmarish Deeping Fen, and if Merry doesn't rescue Teddy, she'll lose him forever. But the further she travels into Deeping Fen's foul waters, the more Merry wonders if she can possibly save her friend - or if she's walking straight into a trap.

Because there's nothing the Toadmen love more than a damsel in distress . . .