Dinosaurs before dark —Osborne, Mary Pope, author.

Eight-year-old Jack and his younger sister Annie find a magic treehouse, which whisks them back to an ancient time zone where they see live dinosaurs.

The knight at dawn —Osborne, Mary Pope, author.

Eight-year-old Jack and his younger sister Annie use the magic treehouse to travel back to the Middle Ages, where they explore a castle and are helped by a mysterious knight.

Christmas in Camelot —Osborne, Mary Pope.

On Christmas Eve, Jack and Annie's tree house transports them to King Arthur's castle at Camelot, where they undertake a quest to the castle of the Otherworld.

Night of the Ninjas —Osborne, Mary Pope.

The magic tree house takes Jack and Annie back in time to feudal Japan where the siblings learn about the ways of the Ninja.

Dolphins at daybreak —Osborne, Mary Pope.

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.

Afternoon on the Amazon —Osborne, Mary Pope.

Eight-year-old Jack, his seven-year-old sister, Annie, and Peanut the mouse ride in a tree house to the Amazon rain forests, where they encounter giant ants, flesh-eating piranhas, hungry crocodiles, and wild jaguars.

Pirates past noon —Osborne, Mary Pope, author.

The magic treehouse whisks Jack and Annie back to the days of deserted islands, secret maps, hidden gold, and nasty pirates.

Hurricane heroes in Texas —Osborne, Mary Pope, author.

"Jack and Annie travel in the magic tree house to Galveston, Texas on September 8, 1900--the day of the worst natural disaster in US history"-- Provided by publisher.

Mummies in the morning —Osborne, Mary Pope, author.

Jack and his younger sister take a trip in their tree house back to ancient Egypt, where they help a queen's mummy continue her voyage to the Next Life.

Balto of the Blue Dawn —Osborne, Mary Pope, author.

"Jack and Annie travel back in time to 1925 Nome, Alaska, where they meet Balto, the famous sled dog, and help save the town from illness"-- Provided by publisher.

A big day for baseball —Osborne, Mary Pope, author.

"Jack and Annie use the magic tree house to travel back in time to 1947 Brooklyn, New York, where they pretend to be batboys at Jackie Robinson's first game with the Brooklyn Dodgers against the Boston Braves"-- Provided...

To the future, Ben Franklin! —Osborne, Mary Pope, author.

"Jack and Annie are whisked back in time by the magic tree house to meet Benjamin Franklin in Old Philadelphia"-- Provided by publisher.

Lions at lunchtime —Osborne, Mary Pope.

The magic tree house takes Jack and Annie to Africa where they meet up with wonderful wild animals, a very hungry warrior, and where they even solve a riddle.

Blizzard of the blue moon —Osborne, Mary Pope.

Dingoes at dinnertime —Osborne, Mary Pope.

The magic tree house whisks Jack and Annie away to Australia where they must save some animals from a wildfire.

Polar bears past bedtime —Osborne, Mary Pope.

Their magic tree house takes Jack and Annie to the Arctic, where a polar bear leads them onto very thin ice.

Twister on Tuesday —Osborne, Mary Pope.

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.

Summer of the sea serpent —Osborne, Mary Pope.

Jack and Annie travel in their magic tree house to the land of the mystical selkies to seek a magical sword for Merlin.

Ghost town at sundown —Osborne, Mary Pope.

Their magic tree house takes Jack and Annie back to the Wild West, where they experience excitement and danger and try to solve a riddle.

Sunset of the sabertooth —Osborne, Mary Pope.