Money machine

Though they were in a multi-day ultra-distance race west of Little Rock, neither Rock nor the group with him questioned why they had set up camp in a parking lot between the Town and Country Shopping Center and a smaller strip mall near one of the city's busiest intersections.
They were across University Avenue from the campus of Arkansas-Little Rock, with miles of city streets and highways between them and the nearest trail.

Rock was there with about ten other people, including Keith Brown and Donna Falkenhain, a couple from the Little Rock Hash he had known for thirty years.

They were near a bricked pavilion filled with vending machines, and Rock noticed one that dispensed boxes of cash. He wasn't sure how the machine worked but suspected it would photograph anyone who made a withdrawal and then send a bill. With little further thought, he got a box and carried it back to camp.

Someone there saw Rock with it and looked at him as if he had lost his mind. "I can't believe you got one of those. Man, you're gonna owe them something like twenty-five percent interest on the money."

"Oh shit. I had no idea," Rock said.

At some point, for a reason he would never understand, Rock left the box unguarded on his folding chair for a few minutes before he realized what a huge mistake that had been. Keith Brown, though lovable and funny, was forever in gambling debt and notoriously untrustworthy among his friends. Rock hurried back to find cash from the box strewn about on the chair. He immediately turned to Donna.

"Do you think Keith got into this?" he said.

She looked at the open box and the money. "I don't know, but he probably did. What I don't understand is why you, of all people, got something like that. Why didn't you just go to a bank?"