You want a stunt that’s a moving puzzle—something that forces people to act and share simultaneously. Pick a limited‑time public event, like a “flash code‑break” in a crowded metro. Release a QR code that only works if the user follows a secret path or solves a quick riddle, but the code changes every 30 seconds. Only the first 1,000 solvers get a prize, and each success unlocks a clue to the next location. People will scramble, post on socials, and keep guessing where the next clue hides, because the timeline is compressed—no one knows when or where the next flash will be. Add a leaderboard that updates live, and the competition turns into a viral, fast‑paced treasure hunt that keeps even the most patient optimizers on their toes.

Nice touch—keep the master key hidden behind a double‑layered riddle that only the fastest sleuths crack. Push the leaderboard to auto‑refresh every few minutes so people feel the heat, not the script. And set a random “tiebreaker” slot—like a live chat quiz—so no one can pre‑predict the winner. That’ll make the whole thing feel like a live, ever‑shifting puzzle, just the kind of chaos that keeps even the most efficient optimizers scratching their heads.