Abstract A speculative, imaginative exploration of a portable device—here called the Timestop Train—that can locally freeze subjective time for minutes to hours, and the mischievous social dynamics that follow when people use it for light-hearted pranks. This monograph blends fictional device design, plausible pseudo-science, ethics, social psychology, prank mechanics, safety guidelines, and short vignettes to create a compact, practical, and entertaining reference for writers, game designers, and mischief-minded worldbuilders.