“I spent a few more minutes puzzling over the timeline before turning my attention to the notebook’s first page, which contained a pencil drawing of an old-school coin-operated arcade game—one I didn’t recognize. Its control panel featured a single joystick and one unlabeled white button, and its cabinet was entirely black, with no side art or other markings anywhere on it, save for the game’s strange title, which was printed in all capital green letters across its jet black marquee: POLYBIUS. Below his drawing of the game, my father had made the following notations: No copyright or manufacturer info anywhere on game cabinet. Reportedly only seen for 1–2 weeks in July 1981 at MGP. Gameplay was similar to Tempest. Vector graphics. Ten levels? Higher levels caused players to have seizures, hallucinations, and nightmares. In some cases, subject committed murder and/or suicide. “Men in Black” would download scores from the game each night. Possible early military prototype created to train gamers for war? Created by same covert op behind Bradley Trainer?”