When spies have a meeting with a stranger, how can they know they’re meeting the right person? Here’s, there’s an offer of some kind on the table. But before it can be accepted or rejected, you must verify the other person. Does this require a high tech solution? Actually, the oldest, simplest solution is still the best. A playing card was torn in two before the meeting and each side given a half. We see his half on the table and hers in her hat. If they match, each is assured they’re meeting the right person. The technique costs nothing and is virtually foolproof.