Ellingham Academy is a famous private school in Vermont for the brightest thinkers, inventors, and artists. It was founded by Albert Ellingham, an early twentieth century tycoon, who wanted to make a wonderful place full of riddles, twisting pathways, and gardens. "A place," he said, "where learning is a game."

Shortly after the school opened, his wife and daughter were kidnapped. The only real clue was a mocking riddle listing methods of murder, signed with the frightening pseudonym "Truly, Devious." It became one of the great unsolved crimes of American history.

True-crime aficionado Stevie Bell is set to begin her first year at Ellingham Academy, and she has an ambitious plan: She will solve this cold case. That is, she will solve the case when she...