12-year-old Matt Lively is obsessed with trying to somehow stretch time to make summer last indefinitely. Convinced he is living the ideal time of life—in Missouri, 1950, between the 7th and 8th grades—he longs to experience extraordinary adventures before he is forced to confront high school, and eventually, boring adulthood. Along with his best friends, Rob Linehart and Wally Carter, Matt begins the summer with pranks, problems and fun. A mysterious and ominous tramp, Thatcher, accosts Matt and Rob and tells them things he should have no way of knowing. As thatcher captures the boys' attention, he invites them back in time to save a life or two and recover a treasure, but mostly to change history in a way that will preserve The Adventures of Tom Sawyer and The Adventures of Huckleberry Finn for posterity. Join Matt, Rob and Wally on their time-traveling adventure of self-discovery.