Celebrate more than 25 years of Horrible Harry with the 30th book in this beloved classroom chapter book series!

Catastrophe strikes Room 3B when the diamond on Miss Mackle's engagement ring disappears. Fortunately, Harry is on the case! The third-grade talent show is coming up, and he wants to show off his skills as South School's greatest detective. Doug, on the other hand, has no idea what to do for his act. The best friends need to find both Doug's talent and the teacher's diamond, or else the talent show will be a horrible disaster for everyone!

A Children's Book of the Month Club Selection

Suzy Kline; Illustrated by Amy Wummer