Their magic tree house takes Jack and Annie deep into the sea, where they meet up with dolphins, sharks, and octopi as they search for the answer to an ancient riddle.

"Marie-Grace can't wait to begin her journey up the Mississippi River with her father. The steamboat they're traveling on is the biggest and fanciest boat Marie-Grace has ever seen. It's crowded with all sorts of interesting passengers, including Wilhelmina Newman, a girl her age. Wilhelmina is traveling alone, and she's carrying a secret in one of her trunks--clues to hidden Gold Rush treasure."--Provided by publisher.

The Gumshoe Gang has their next case and it hits close to home. One of their own detectives is missing his RC race car and has to crack the ransom note! Caleb needs his car back in order to compete in the school's RC race car race on Sunday and he has no time for these nonsense riddles. Can his friends help him crack the notes? Who would steal a RC race car anyway? And why does it smell like rotten eggs? These mysteries are perfectly suited to keep...

A sultan's daughter who loves numbers and riddles devises a plan to find the man who is best suited to be her husband.

Flying horses from the Royal Guard arrive in Crystal Cove to deliver a message for Sasha, but in order to open it she must first solve a riddle, which requires her to find the petals of rare and different-colored flowers.

A series of riddles that first give descriptions of various flowers and then reveal their names.

The Boxcar Children discover an old wedding photograph and a riddle while on a visit at a neighbor's house, and they embark on a spy game designed by the house's original owner.

Invites the reader to solve the riddle of why Silly Milly likes certain things and dislikes others.

Silly Milly is going on a trip, but what is she packing?

Destiny leads Rowan of Rin to make choices which could save a powerful crystal, thereby ensuring the safety of his people and his people's shore-dwelling allies.