While spending the summer at their grandmother's Vermont inn, two prankster siblings awaken young ghosts from the inn's distant past who refuse to "rest in peace.".

Froggy, having built a tree house with his friends and decided on a boys only rule, is surprised when Frogilina helps save his pizza party.

When Jack and Annie travel back to the Kansas prairie in search of "something to learn," they gain an understanding of how hard life was for pioneers and they experience the terror of a tornado.

Tired of the rules that have bound them ever since "the bad thing happened," twelve-year-old Diana ignores her brother's warnings and befriends the daughter of the new caretaker, setting in motion events that lead to the release of the spirit of an evil, crazy woman who once ruled the old Willis place.

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.

Using their magic tree house, Jack and Annie travel back to the time of the American Revolution and help General George Washington during his famous crossing of the Delaware River.

When the Stein's are shown a rundown castle complete with ghosts and goblins, they indicate it is the "house of their nightmares" and take it.

Jess needs a fresh start. She's broke and alone, and she's just left her job under less than ideal circumstances. Her half-brother Ben didn't sound thrilled when she asked if she could crash with him for a bit, but he didn't say no, and surely everything will look better from Paris. Only when she shows up, to find a very nice apartment, (could Ben really have afforded this?) he's not there. The longer Ben stays missing, the more Jess starts to dig...

The magic tree house carries Jack and Annie to New York City in 1938 on a mission to rescue the last unicorn.

"Jack and Annie are magically transported to mid-1800's Thebes where they are saved from a dangerous accident by Florence Nightingale!"--Publisher.