Horrible Harry and friends start off third grade with a new room and a field trip to an old copper mine to study rocks.

The students in Miss Mickle's third-grade class enjoy a boat trip on the Connecticut River after a class discussion of ancestors reveals that Sidney and Ida both have connections to the sea.

Yasmin's class is going on a field trip to the zoo, and Yasmin is thrilled when she is chosen to help feed the monkeys; but when she trips and spills their food both she and the monkeys are upset--until she remembers that she has fruit in her lunch bag to share with her new "friends."

James "Gum" Shoo's art class heads to the museum. They've been learning about forged art, but they never expected to find a fake in the gallery! Only Gum and his gumshoe friends will be able to solve this museum caper.

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.

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.

While in New York City on a field trip, Samantha "Sam" Archer and her friends find themselves immersed in a run of crimes at sightseeing locations.

Molly's class is going on a field trip to the Space Science Center, but Molly thinks they'll be blasting off into outer space. Everyone tries to tell Molly that the trip won't involve visiting outer space, but Molly is sure they're all wrong. When Mr. Rose confirms that they will be keeping their feet on Earth, Molly comes up with a secret plan. Will Molly's secret plan send her into space? Or will she remain grounded?

Sam, Egg, Gum and Cat, and the other members of the Franklin Middle School Science Club are on a guided tour of Greater River City Air Force Base (otherwise known as Zone 99), an aspiring science museum, and Gum is convinced that if they can sneak away from the group they will find evidence of aliens--and it is up to the reader to choose how their adventure unfolds.