Last July, my 12-year-old car died on California's Santa Ana Freeway. It was an hour before sunset, and I was 25 miles from home. I couldn't reach anyone to pick me up, so I decided to take a bus. Not knowing the routes, I figured I'd just head east.

A bus pulled up, and I asked the driver how far she was going. "Four more lights," she said. There was another bus I could take from there. This clearly was going to be a long night.

She dropped me off at the end of her route and told me which bus to look for. After waiting 30 minutes, I began to think about a very expensive cab ride home. Then a bus pulled up. There was no lighted number above its windshield. It was out of service. But the door opened, and darned if it wasn't the same driver.

"I just can't leave you here," she said. "This isn't the nicest place. I'll give you a ride home."

"You'll drive me home in the bus?" I asked, perplexed.

"No, I'll take you in my car," she said.

"It's a long way," I protested.

"Come on," she said. "I have nothing else to do."

As we drove from the depot in her car, she began telling me a story. A few days earlier, her brother had run out of gas. A good Samaritan picked him up, took him to a service station and then back to his car. "I'm just passing the favor along," she said.

When I offered her money as a thank-you, she wouldn't hear of it. "That wouldn't make it a favor," she said. "Just do something nice for somebody. Pass it along."