The story follows a group of enterprising young motion-picture exhibitors and their backer as they partner with an absent-minded but brilliant professor to create a Boston photo-playhouse devoted to educational films. The boys confront rival exhibitors, sabotage, accidents and mysteries—including a missing satchel, a railroad wreck, strange desert camels and a shipwreck near Plymouth—while staging inventive exhibitions and rescuing a captured comrade. The narrative balances technical showmanship and youthful resourcefulness, culminating in the successful realization of the professor’s plan and the boys’ cinematic triumph.