Framed for an epic prank, the now famous "Detention Adventure Four" – Raign, Brett, Joy, and Hulk – must team up with new ally, Kelly, to hunt for the legendary lost fortune of Ignatius Cockshutt. Their punishment lands them roles in the local Brantford Historical Society's reenactment play under the hawkish eye of historian Miss Dumont. Delving deeper into history unearths surprising truths about the town's past, while leading them closer to their goal. When it becomes clear that a mysterious foe is racing them to the treasure, they have to work against the clock, create unlikely alliances, and face hard truths.