When Samantha "Sam" Archer and her friends in the nature club arrive in Yellowstone Park on a school trip, they find that the park superintendent's son may have been kidnapped.
Catalina "Cat" Duran and her sixth-grade class are on a bowling trip, but in one lane the ball keeps going mysteriously off track, so the four friends decide to investigate the problem.
Edward "Egg" Garrison and his friends are on a field trip to watch the local minor league baseball team, but a theft at the concession stand is delaying the game, so the four sixth-grade detectives decide to investigate.
The Haunted House ride at Fun City is rumored to be haunted by the ghost of someone who died there, and when Samantha "Sam" Archer and her friends get trapped inside they need to find the truth.
On a science class trip to the aquarium, Catalina "Cat" Duran and her friends discover that two of the seals have been drugged and investigate to discover the person responsible.
Samantha "Sam" Archer, her friends, and their "kindergarten buddies" are on a trip to the River City Children's Museum, which has been plagued by vandalism, and it is up to the sixth-graders and their new buddies to figure out who the vandals are and why they are set on closing the museum.
When Catalina "Cat" Duran and her friends in the History Club arrive at Mount Rushmore on a school trip they find that someone is playing dangerous tricks and trying to drive people away from the park.
While their sixth-grade class is on a field trip to Everglades National Park, James "Gum" Shoo and his friends find a suspicious park ranger and a gang of poarchers.