Your mission, should you choose to accept it: 2.5 hours in Harpers Ferry without blowing your cover. In plain terms: your team explores on foot and takes on spy missions together. The sights are nice. The real entertainment is your team: the debates on street corners, the plans that almost work, and the one person who takes it far too seriously. The missions are only half the game. The other half is watching each other, because at the final stop your team votes on who might be a double agent. There may not be one at all. No app, no guide, no headset. About 2.5 hours and 3.1 km, with 4 stops that stay secret until you earn them. You leave with your cover blown, your cheeks sore from laughing, and photographic evidence of both. Who it's for: friends, couples and families with teens; and private groups, from bachelor and hen nights to work teams and active over-55s. Book a private game for 1 to 8 players on a date you choose; a team of one works too. Bigger groups play as several private teams.