Ten-year-old Lucy, an orphan who wants a little sister more than anything, finds a very special one in the less than perfect family which she joins.

With goblins, trolls, and the house boggart all trying to get them, the Grace children turn to Great Aunt Lucinda for help.

Life seems to be back to normal for "newly twinned" sisters Miri and Molly until their magical house sends them on new time-traveling adventures, including meeting Molly's mother in 1918 and saving two unusual soldiers during the Civil War.

Fleeing Southerland Plantation with his little sister, twelve-year-old Homer finds a secret community called Freewater, created by formerly enslaved people, but when he learns of a threat that could destroy this place, he crafts a plan to help his new home.

Amy and Dan Cahill travel to Australia to figure out what their own parents knew about the object of their quest, but their search brings back terrible memories for Amy and endangers a secret ally.

An escalating race to find the 39 Clues finds Amy and Dan pursuing a Clue guarded by thousands of the world's best-trained soldiers, an effort that separates them in explosively dangerous ways.

When the Aldens agree to watch the house of a local author who has written a book about a vampire, they end up investigating activities that are suspiciously similar to those in his book.

While vacationing at an aquarium in Florida, the Aldens soon discover that the shark is in danger--someone at the park wants it gone.

The magic tree house takes Jack and Annie to Antarctica to search for the fourth secret of happiness for Merlin.

When they take their dog, Watch, for obedience training, the Alden children discover that some of the dogs in the class have vanished and decide to try to solve the mystery of their disappearance.