While visiting their friend Wallis and her adopted daughter on Mount Desert Island, Maine, Josh, Dink, and Ruth Rose investigate why three white wolf cubs were stolen, and by whom.
Reports of zombies and grave-robbers alarm the people of a Louisiana swampland village, but Ruth Rose, Josh, and Dink begin to suspect that the supernatural may not be the cause of the eerie occurrences.
When the umpire at the baseball game fundraiser is accused of stealing a collection of autographed baseballs, Dink, Josh, and Ruth Rose try to prove his innocence.
Dink and his friends meet an exchange student, Sammi, who is actually the prince of an island country, hiding from those enemies who have kidnapped his parents and who may be after him as well.
Someone has been stealing and leaving behind little green sneakers, so Bradley, Brian, Nate, and Lucy trail their new teacher, who wears the same shoes in normal size.
Bradley, Brian, Nate, and Lucy try to help out the Flying Fortunatos, an acrobatic troupe with a very shabby traveling circus, by identifying the marvelous, hooded trapeze artist they spied rehearsing.
When doctored photographs of the President of the United States appear after an innocent Halloween party, his stepdaughter KC and her friend Marshall have to find the culprit in order to save the President's chances for re-election
Bradley, Brian, Nate, and Lucy enter Polly the pony and Pal the dog in a July 4th pet costume contest, but when Independence Day arrives the animals are nowhere to be found.
When Ruth Rose and her friends, vacationing in Florida, discover that her grandmother is about to invest in a project to recover sunken treasure, they stumble upon evidence that the entire plan may be a fraud.
Dink, Josh, and Ruth Rose investigate the disappearance of a valuable racehorse that Dink's uncle and his friend, Forest Evans, have just bought and entered in a race at Saratoga.
As a Father's Day gift to the twins' Dad, Bradley, Brian, and their cousins Lucy and Nate try to identify and stop whatever creature is biting fruits and vegetables in the garden.