After a slight misunderstanding involving a horrible governess, oatmeal, and a jar of tadpoles, siblings Tobias and Charlotte Eggars find themselves abandoned by their father at the gates of a creepy reform school. Evil mysteries are afoot at Witherwood, where the grounds are patrolled by vicious creatures after dark and kids are locked in their rooms. Charlotte and Tobias soon realize that they are in terrible danger—especially because the head of Witherwood has perfected the art of mind control.

If only their amnesiac father would recover and remember that he has two missing children. If only Tobias and Charlotte could solve the dark mystery and free the kids at Witherwood—and ultimately save themselves.