Dink, Josh, and Ruth Rose head to Florida where they uncover a scam at a local space memorabilia attraction.

KC discovers that the President of the United States has been replaced by a clone and sets out with her friend Marshall, on a dangerous mission to set things right.

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.

When Dink, Josh, and Ruth Rose visit Washington, D.C., just before Christmas, they are inadvertently caught up in a kidnapping plot that was intended for the president's dog, but also involves the president's stepdaughter and her friend Marshall.

Dink, Josh, and Ruth Rose are enjoying Halloween fun in Sleepy Hollow, New York, but when unplanned spooky things start happening, they investigate whether a real headless horseman might be to blame. Look for a hidden message inside this book!

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.

KC and her friend Marshall accompany KC's stepfather, the United States President, to remote Camp David, where they find clues that point to either ghostly or criminal activity.

KC and Marshall investigate the theft of a precious emerald, brought by representatives of the Chinese government to bring luck to two baby tigers born at the National Zoo.

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.

While investigating a mystery on New Year's Eve, four friends encounter a big surprise.