A.J. and his classmates are convinced that the new school librarian, Mrs. Roopy, has multiple personality disorder because she keeps pretending to be famous people.

Resolving to earn so much money that his mother will no longer stress out over the bills, eleven-year-old Timmy Failure launches a detective business with a lazy polar bear partner named Total but finds their enterprise "Total Failure, Inc." challenged by a college-bound spy and a four-foot-tall girl whom Timmy refuses to acknowledge.

Timmy Failure, founder, president, and CEO of the greatest detective agency in town, perhaps the nation, is about to crack the biggest case of his generation: a school competition to find a stolen globe.

Roscoe cannot wait to tap dance in the school talent show until some older boys make fun of him and say that tap dancing is just for girls.

Having gotten a pair of hard-to-find Walkie Talkie shoes, Roscoe is suddenly popular and wants his best friend, Gus, to join the fun, but before Gus's parents will buy him new shoes, he must wear out his long-lasting sneakers.

A.J. and his friends find out what amazing things Miss Lazar, the Super Custodian at their school, can do.

Disaster reigns when A.J. participates in the school's holiday pageant celebrating Christmas, Hanukkah, and Kwanzaa.

A.J. thinks that nothing can possibly be as boring as a sleepover in the natural history museum. But anything can happen when Ms. Krup is in charge. The tour guide says that dinosaur skeletons come to life in the middle of the night. Is she right?

This book was never meant to exist. No one needs to know the details. Just know this: there's a Merry, a Larry, a missing tooth, and a teachers' strike that is crippling Timmy Failure's academic future. Worst of all, Timmy is banned from detective work. It's a conspiracy of buffoons. He recorded everything in his private notebook, but then the manuscript was stolen. If this book gets out, he will be grounded for life. Or maybe longer. And will Timmy's...

A.J. and the other students at Ella Mentry School brave trick-or-treating at the school secretary's house, even though it is supposedly haunted.