Beanotown - for the first time in Dennis's life - has become boring. All Dennis's pranks are backfiring and he seems to have lost his awesomeness. Even his faithful hound, Gnasher, seems fed up with him these days. If only there was some way to bring the fun back to Beanotown...

When Dennis hears about the legendary Golden Pea-shooter of Everlasting Fun, it sounds like the only thing that can solve his problems and return his hometown to its former glory. With the help of his cousin, Minnie, and Gnasher, Dennis must go on a quest, discovering the mysterious Chamber of Mischief in his bid to find the Golden Pea-shooter; but a series of tricky challenges (and Dennis's nemesis, Walter) stand in his way.

Dennis's latest and, quite possibly, greatest adventure is filled with epic fun, from ghostly Vikings and skateboarding Grandmas to an enormous Gnashersaurus-Rex and a series of interactive puzzles for YOU, the reader, to complete. Can YOU help Dennis solve the fiendish mystery and save Beanotown from eternal boringness?