When the Hardy Boys set out to solve the mystery of their missing chums, they discover a gang hide-out in a cave on an island along the way.

When George takes a delivery job for a local pharmacy, three customers fall prey to lethal poisons that are substituted for medicine, and Nancy must solve the case before George is named a prime suspect

Dink and his friends unearth the mysterious truth behind the envelopes incorrectly delivered to his house.

Scooby and the gang, planning on a little fun in the sun, head to the Ocean Land water park, but a slimy sea creature is haunting all the rides and scaring away the kids.

In this third book, there's a fire on Orange Street and a shop burns down! Mrs. Brown thinks her candles started the fire. She's so upset she won't leave her house. But the town pet parade can't start without her! Hilde needs to find out what REALLY caused the fire. Can she crack this RED-HOT case in time to save the parade?

America's Sherlock Holmes in sneakers continues his war on crime in ten more cases, the solutions to which are found in the back of the book.

Readers can read the story and try to figure out the clues along with Marie and her pals, and can find out if they solved the mystery correctly by checking their answers at the back of the book.

While visiting Wallis's castle, Dink and his friends investigate strange noises that lead them to a dangerous secret.

When Jeremy and Jason are left to run the family skiing business, strange things begin to happen, starting with a fire in the snowmobile garage.

While at a garden party, Keisha overhears a conversation about an explosion and begins to look into the matter more closely, only to realize that something is terribly wrong, but without any proof, she cannot stop what is planned.