In the Arctic, a native seal-hunter and the animals of the north show Jack and Annie their
way of life while the kids solve the final riddle in their quest to join the Ancient Society
of Master Librarians.
— Michael Main
The tree house was on the ground. There were no trees and no houses, only an endless
field of ice and snow.
DEBUT
Polar Bears Past Bedtime (Random House, April 1998).
VARIANTS
Debut. Polar Bears Past Bedtime (Random House, April 1998).
Circa AD 2000 to 2099: The entire trip is presumed to take place in the kids’ present day, with the only time travel being that they return to the exact moment of their departure.
Timeline Models
Single Static Timeline: Within the series, anything the kids do seems to fit known history rather than change it.
From the magic tree house in Frog Creek, Pennsylvania, circa 2019 ⋙ to the Arctic, possibly in the kids’s present day. Round trip. Note: The only certain time travel is that they return to their exact departure time.
From the magic tree house in Frog Creek, Pennsylvania, circa 2019 ⋙ to Camelot. Note: Morgan le Fay in the treehouse.