Matt, Q, Tony, and Hooter are all friends that started an adventure club. The first Adventure Club meeting is a camp out in Tony's backyard. Matt's parents made him bring his little sister Katie. The boys and Katie decide walk down to the Levart Lake for a little more excitement. Tony tells them about a mysterious boat that appears there and takes people on adventures.
The boys and Katie see the a boat and are drawn to climb in. The next thing they know they are in the icy Delaware River on the night of the Battle of Trenton in 1776. Katie falls in the icy water and is saved by George Washington. The children are going to be taken to safety when Matt runs back to return George Washington's cape. The children are separated and Matt is sent marching with the patriot army.
Matt meets a soldier named Israel. They become friends and promise to stick together. Israel becomes sick and dies. Mr. Horbee finds them and brings Matt to safety. Then next day Mr. Hornbee gives Matt his mule and sends him along the trail to find his way back to the river.
Matt hears noises in the woods and is stopped by Native Americans. As they are about to capture Matt, Hooter and Tony jump out and stop them. Katie and Q were taken by Hessian soldiers The Natives Americans take the boys to the Hessian camp where they find Katie and Q.
Patriot soldiers find the boys and Katie with the Gustav, the Hessian soldier that they killed. The patriots believe the kids are spies and are about to bring them to jail when George Washington arrives and recognizes the boys and Katie. George Washington gives his extra socks to Katie so she can stay warm. Katie spots the boat to get home. She hops in and the boys realize she found the way home.
When the boat settles the boys are in warm weather and realize they have left 1776. When the fog settles they can see Tony's backyard. They decide to keep the adventure a secret and hide the boat. Katie agrees to trade George Washington's socks with Q for a bag of marshmallows. Everyone is happy to be home.