Seven-year-olds Bradley, Brian, Nate, and Lucy make observations and gather clues that convince them that their older siblings, cousin, and animals have been captured by hungry space aliens.
When three leprechaun statues disappear just before St. Patrick's Day, Bradley, Brian, Nate, Lucy, and other friends follow clues in order to prove that Lucky O'Leary is innocent of the crime.
Bradley, Brian, Nate, and Lucy visit a haunted hotel on Halloween, but once inside they realize that they have seen plenty of people going in and none coming back out.
KC discovers that the President of the United States has been replaced by a clone and sets out with her friend Marshall, on a dangerous mission to set things right.
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.
