Excluded from her friends' new club, the Pain Sisters, because she has never broken a bone or been to the hospital, Libby takes her grandfather's jar of gallstones to school and pretends they are hers.

Annie Colwater's husband has just confessed that he's in love with a younger woman. Devastated, Annie retreats to the small town where she grew up. There, she is reunited with her first love, Nick Delacroix, a recent widower who is unable to cope with his silent, emotionally scarred young daughter. Together, the three of them begin to heal. But just when Annie believes she's been given a second chance at happiness, her world is turned upside down...

Dolphins at daybreak: 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. Ghost town at sundown: 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. Lions at lunchtime: The magic tree house takes Jack and Annie to Africa where they meet up with wonderful...

The magic tree house whisks Jack and Annie to the vast plains of Africa to solve a new riddle. Soon they have an adventure with wildebeests, hyenas, zebras, and elephants. Will Jack and Annie come back safely? Or will lions get in their way?

Their magic tree house takes Jack and Annie back to a monastery in medieval Ireland, where they try to retrieve a lost book while being menaced by Viking raiders.

Travel to Ancient Greece with Jack and Annie as they meet Alexander the Great and help tame his wild stallion.

Two children, Jack and Annie, discover a mysterious tree house and are swept away on adventures in Elizabethan England, the mountains of Africa, Plymouth, Massachusetts, for the first Thanksgiving, and the Hawaii of long ago.