Dori Hillestad Butler's books have appeared on children's choice award lists in 18 different states. Trading Places with Tank Talbott won the Maryland Children's Choice Award in 2007. And The Buddy Files: Case of the Lost Boy won the 2011 Edgar Award for Best Juvenile Mystery. Dori has also been a ghostwriter for the Sweet Valley Twins, Unicorn Club, and Boxcar Children series, and a children's book reviewer for several publications. She's published numerous short stories, plays, and educational materials, and has served as the Iowa Society of Children's Book Writers & Illustrators' Regional Advisor. She grew up in southern Minnesota and now lives in Coralville, Iowa, with her husband, son, dog, and cat. She visits schools and leads writing workshops all over the country.

Kaz and Claire's new detective agency is a success! Their latest case, though, is proving to be the hardest yet. When Claire's classmate says he saw a ghost backstage while rehearsing the school play, Kaz goes to school with Claire to investigate. From the description the boy gave, Kaz is sure it's his mom—but where has she gone? Kaz and Claire search everywhere and find no trace of her, but the mysterious ghostly activities are still happening...