In 1971, driving from Eau Claire, WI, to Denver, I picked up a hitchhiker somewhere in Iowa who was also headed for Denver. When the gas gauge got down to 1/4, I started looking for a filling station, but that was insufficient prudence in Nebraska on I-80 at night. One after another was closed, and I ran out of gas. I emptied my camping stove into the tank, and that got us a little way, but a couple of miles short of the next exit, at which there was an all-night truck stop. So, leaving the hitchhiker with the car, I set off on foot on the shoulder with my headlamp. Some trucks passed, but did not stop for me. At length, a car stopped & picked me up. It was my car. A driver _going east_ had seen my car on the other side, guessed what had happened, gone to the next exit, turned around, gone to the truck stop, bought a gallon of gas, made the circuit again, delivered it to the hitchhiker, and sped off without introducing himself or accepting payment. (We got to Denver at 3 a.m. He put me up at his place so I would not have to wake up the people I would be joining. He was gay, and it would perfect the story if I said I had gotten laid, but that would be a lie, and this is a moral thread.)