Ashamed of his wimpy younger cousin, eight-year-old Jimmy is determined to keep him out of his special club for rough, tough, and terrible boys, until an accident involving Jimmy's father demonstrates for him the true meaning of courage.
The Dangerous Snake and Reptile club, with the help of a boy visiting the neighborhood, sets up equipment in the clubhouse in hopes of tracking flying saucers and making contact with aliens.
The members of the Werewolf Club, transported to 1890 London by Uncle H. G. Talbot's time-and-space machine, assume their werewolf forms in order to help legendary detective Sherlock Holmes stop the theft of England's crown jewels.
Danny, Robert, Mike, and their friends form a club, collect and display a dinosaur bone, tadpoles, and a king snake that the brothers found on vacation, as well as creatures from their neighborhood.
With the help of their favorite teacher, two rival clubs, the all-boy Copycats and the all-girl Tattletales, stop trying to out-do each other long enough to help the ghosts of a baby elephant and a herd of mastodons that appear near their small Vermont town.
Sixteen-year-old Guy Langman, his best friend Anoop, and other members of the school Forensics Club investigate a break-in and a possible murder, which could be connected to the mysterious past of Guy's recently-deceased father.
