I FOUND MY target easily enough: a boy about thirteen, still young enough to be on vacation with Mom and Dad, but old enough to escape them when he could. He stood outside the T-shirt store, reading the off-color slogans.

As I approached, his face reddened as if he’d been caught doing something he shouldn’t.

“Hey,” I said, flashing a big smile. “Do you have a second?”

“Uh, sure.”

I motioned to Sunken Treasures across the road. “There’s something in there I want to get for my boyfriend, as a joke, but I’m, well, kind of embarrassed to buy it. It’s a shell with a woman in a bikini on it.”

To an adult, this would seem strange. But to a thirteen-year-old, all adults are strange, their motives inexplicable. I described the shell and gave him a twenty, with the promise of another when he returned.

Fifteen long minutes later, he was back, empty-handed.

“They have a rack of conch shells and some of them are painted, but none with girls in any kind of bathing suit.”

“Huh. Must have been a different store, then.”

I let him keep the twenty and he disappeared into the T-shirt shop.

My next mark was a fortyish man who sucked in his spare tire as I drew close. For him, I had a new story: I’d been in the store the night before with friends, some of whom had been drunk and made a scene. I really wanted this shell for my brother, but I was afraid the store owner would recognize me and kick me out.

He too returned empty-handed. “It’s behind the cash register,” he said, handing me back my twenty. “And it’s not for sale. I tried, but the guy said a friend of his had painted it and it was only for display. Sorry.”