The problem now is that how exactly do you design a test that's 'who can smell alcohol.' Strange pauses for a moment, then brightens up as an idea comes to him.

"Don't let anyone take my seat," he says, as he gets up from the table. When he returns, he's carefully balancing a tray with five or so shotglasses on it, each one holding a clear liquid.

"One of these has alcohol in it—and I don't know which one it is either, the bartender set them down when I wasn't looking. We'll examine the glasses, take a sniff but not drink anything, then guess which one has alcohol."