01 / A CARD FINDS ITS WAY HOME
The 21-card trick
Remember a card. Follow it through three deals. See what arrives at the end of the story.
Deal me in →← Back to the theater
THE INTERACTIVE THEATER
A little mystery, just for you.
No preparation. No account. Just a thought to keep to yourself, and a few choices to make.
These are playful mathematical mysteries. Each has an optional explanation when you’re ready to look behind the curtain.