Jack and Annie wonder when the Magic Tree House whisks them to the Wild West. But before they can say "Boo!" they rush headlong into an adventure filled with horse thieves, a lost colt, rattlesnakes, and a cowboy named Slim.
Someone has frozen time in order to steal four of the world's most valuable treasures. And the thief is wearing a black mask like Maximum Boy, a silver cape like Maximum Boy, and a hat with his logo on it.
Eleven-year-old Miri Gill feels left out in her family, which has two sets of twins and her, until she travels back in time to 1935 and discovers Molly, her own lost twin, and brings her back to the present day.
When her embarrassing middle name is revealed at school, mad scientist Franny K. Stein experiments with time in order to return to the past and give herself a more dignified name.
After falling through his computer screen, Zack travels back in time to a school in 999 A.D. where the students believe the world will end in the new millennium.
