Typically Mr. Chhantyal, to avoid complications from one-way streets, would park and wait for Mr. Sherpa on busy Broadway, which comes to life early with cabs and service vehicles headed toward Manhattan. But on this morning, Mr. Sherpa saw that his partner had parked on deserted, residential 62nd Street. As usual, Mr. Chhantyal stepped out to give Mr. Sherpa the driver’s seat. But, strangely, he let the door close and lock. As Mr. Sherpa fished for his duplicate key, he recalled, he felt the first blow.

“I could not understand what was happening,” Mr. Sherpa said. “This man, my partner from my own country, he’s trying to kill me. He was a crazy man, like he didn’t know me. He said nothing  he just kept chopping me.”

The two men had shared little of their personal lives, but Mr. Sherpa had never seen his partner excited or unhinged, not even the one time Mr. Chhantyal visited his home. He came with a mutual friend, stayed late and left drunk on the homemade rice wine that Nepalis call chhaang, Mr. Sherpa said. Mostly, they exchanged pleasantries for a few minutes twice daily; each Wednesday, they went together to Woodside Management on Roosevelt Avenue, passing $700 apiece under the bulletproof glass to Sabur, the dispatcher.

The two were from different sectors of Nepali society. But both came from big families whose political affiliations had made life difficult amid the country’s current civil strife. And both left small villages in the country’s midsection to seek political asylum in the United States. They were most comfortable speaking different dialects but would chat in Nepali while handing off the cab each dusk and dawn.

As Mr. Sherpa’s name implies, he belongs to the renowned tribe of mountain people who have helped many a foreign adventurer up Mount Everest. The Sherpas’ reputation for being trustworthy and tireless guides translates well to the profession of ferrying people around the more flat  but perhaps equally daunting  streets of New York.

Mr. Sherpa grew up in the Sindhupalchok District, in the Bagmati Zone, not far from Katmandu. He arrived in New York in 2001 and had been driving cabs pretty much since. He and his wife and baby live with his sister-in-law and nephew, paying $1,500 a month for a two-bedroom apartment on 62nd Street furnished with a small sofa and two junior mattresses on the floor covered with faux tiger-skin quilts; idealized illustrations of the Manhattan skyline hang on the walls.

Mr. Chhantyal was a member of the Chhantyal caste, which boasts its own proud heritage of valorous copper miners and mythical origins. He came from a village in the Myagdi District.