The laboratory where I worked was just ten minutes on foot from the supermarket. The laboratory also had freezers. Being somewhat of an ice cream junkie, anytime there was a sale, likely as not I’d walk over during my lunch hour to take advantage of it.

The shortest route was via Carlisle Street, a single short block terminating at opposite ends on Pine and Lombard. There’s very little traffic, pedestrian or vehicular. A hot summer midday found me on this deserted street, returning to the lab with a satisfying day’s purchase — and anxious to get it into a freezer as soon as possible. That’s when an unexpected encounter almost derailed my plans.

“This is a holdup,” said a most unthreatening voice behind me. I didn’t have time for games, what with my ice cream rushing to equilibrate with surrounding temperature. So I ignored the voice. But my unseen pursuer must have thought I hadn’t heard him. He repeated, “This is a holdup.”

I turned around and found myself face to face with a young man about my height (5 feet 6 inches in those days) and weighing at most 130 pounds. There was no menace in his eyes as he held out his left hand, the right one hidden behind his back

I was intrigued by his posture and, momentarily forgetting my hurry, prepared to enter into a conversation, so I asked, “What’s in your right hand?”

“A gun,” he said matter-of-factly.

“Oh,” I answered, chagrined at not having a follow-up question ready. I didn’t believe him, of course, but I had read that it’s not a good idea to quibble about facts in such cases. So I waited.

“Give me your money.” I had anticipated something along those lines.

“I don’t have any,” I replied as innocently as I could. “I just spent it at the supermarket.” For evidence, I held out the shopping bag. He likewise declined to quibble about minutiae (not even a few coins, by way of change?); instead, he advanced to the next level. “You have a credit card?”

He evidently wasn’t going to give up without exploring options, and anyway I no longer wanted to see what he had in his right hand. So I fished in my pocket. As I withdrew my wallet, I noticed a man turning the corner on the opposite side of the street and walking in our direction. He must have seen the back of the man facing me, but he continued walking as if nothing he saw was out of the ordinary. Unfortunately this failed to reassure me, because there are probably lots of guns behind backs in South Philadelphia, all poised to come round to the front when summoned; that would explain the man’s indifference. With resignation I produced a credit card and offered it to my new acquaintance, who took it in his left hand.

“You got a PIN number?” Part of me wanted to admonish him for the redundancy: The N stands for number, you dolt, I wanted to say; you don’t have to repeat it! But he might have misunderstood. I still wasn’t too sure about his mental agility, and he might have responded by showing me what I didn’t want to see.

So I said, “Yeah.”

“What is it?” That was better. Now I felt like congratulating him on his logical train of thought. But I didn’t; he might have thought I was being sarcastic, so I gave him a brand new PIN.

“Write it down,” he said, almost respectfully.

“No, you write it down,” I answered. Impatience may have been starting to show in my tone, and I was afraid I was provoking the hidden hand. To my relief, he didn’t get mad; instead, he asked for a pen. I held one forth, and he took it in his left hand, which already held the card. “I can’t write on this card. You got a piece of paper?”

Wondering whether his next request would be for directions to the nearest ATM, I said, “Look, I’ve got ice cream in this bag. It’s melting. Can we get this over and done with, so I can put it in the freezer?” I pulled out a piece of paper, which he also took in his left hand.

“Satisfied?” I asked.

“Yeah.”

“Still remember the PIN?”

“Yeah.” To show he wasn’t bluffing, he repeated it, correctly except for two of the four digits. I shrugged. His version would work as well as the one I’d given him.

I watched as he backed away, card, pen, and paper in the left hand and a gun — of course — out of sight in the right. I would have enjoyed seeing him walk backwards half a block to the corner, never mind the ice cream. But thrift, and the anticipation of gustatory delight, won out. After all, wasn’t that what I’d spent all my money for?