When Jack and Annie are whisked back in time by the magic tree house, they find themselves in Old Philadelphia in 1787. Their mission? Help Dr. Ben.
It isn't hard to find him--Dr. Ben is none other than Benjamin Franklin! But to help him, Jack and Annie have to do something they've never done before. Something daring, dangerous, and almost impossible.
Travel through time and history in this magical and surprising edition of Mary Pope Osborne's New York Times bestselling Magic Tree House series.

Track the facts with Jack and Annie in the nonfiction companion to this book: Benjamin Franklin.

Did you know that there's a Magic Tree House book for every kid?
Magic Tree House: Perfect for readers who are just beginning chapter books
Merlin Missions: More challenging adventures for the experienced reader
Fact Trackers: Nonfiction companions to your favorite Magic Tree House adventures

If you're looking for Merlin Mission #32: Winter of the Ice Wizard, it was renumbered as part of the rebrand in 2017 as Merlin Mission #4.