Four days into my trip, Thyago emailed with news. A friend of his thought that Burri’s picture was made from the top of a building that once belonged to the Bank of the State of São Paulo. That building, still informally called the Banespão, was completed in 1947, and was for a while the tallest in Brazil. I went up with a small group of tourists. It was midmorning, the rain had stopped; we were limited to five minutes. From the viewing platform, 36 floors above the sprawling city, the vista was bright. I took photos in all directions and realized, with a sinking feeling, that I was again in the wrong place. Then the five minutes were up, and our small group had to descend.

A dead end. I wrote to thank Thyago anyway, and I asked other friends in the city about Burri’s picture, but few of them knew it. The search had begun to take on some of the dream logic of the photograph itself. I was frustrated but also vaguely amused, as though I were suspended in the first half of an uncompleted joke. I asked the concierge. I asked the taxi drivers who took me around. None of them could recognize the photograph. It seemed that I would leave São Paulo empty-handed. In any case, the city had grown so fast and so quickly: Perhaps the building the men walked on, or the one from which Burri took his picture, had been altered or demolished.

Then Thyago wrote back. His friend, he said, insisted that it had to be the Banespão. It could be no other. But I’d seen the view with my own eyes. What had I missed? It was a Friday, the day before the end of my vacation. And that was when I remembered a curious story that Burri told about the photograph. In those days, according to Burri, Henri Cartier-­Bresson, a founder of Magnum Photos, limited his fellow photographers to lenses from 35 millimeters to 90 millimeters. Burri had surreptitiously gone longer while shooting in São Paulo, to 180 millimeters. ‘‘I never told him!’’ he said. ‘‘At that point, I broke loose from my mentor.’’ When you shoot at such an extended focal length, there’s a great deal more compression between the middle and far distances. The canyons created by São Paulo’s high-rises seem even more vertiginous. The angle of view is also severely narrowed, cutting out much of what the eye sees on the periphery of vision. Perhaps using the wrong lens was getting in my way? I’d taken a 50-millimeter lens with me. I now borrowed a longer lens from Thyago; it was only 85 millimeters, not ideal, but closer. Then I got in a taxi and went to the Banespão.

It was late afternoon, and by now the rains were torrential. The city was a gray blur. The buildings shone with wet. The time limit at the top of the building was the same as before, five minutes, and in the open-air viewing platform, I got drenched. I set my eye to the camera’s viewfinder and looked northwest. Suddenly, everything clicked into place, as in the final moves of a jigsaw. I saw Burri’s view. To the right was the building the men had walked on. How could I have missed it before? It was (I later discovered) the Edifício do Banco do Brasil. What I hadn’t seen in Burri’s photo was that the ‘‘roof’’ the men were walking on was not the building’s summit: The building had a stacked design, and a further set of floors rose just out of the shot. To my left and far below, meanwhile, was Avenida São João, slightly changed from 1960 — the tram lines were gone — but certainly recognizable in its rain-slicked state. The avenue was full of cars, buses and pedestrians. The rain kept coming down, and my five minutes were up. But the mission had been accomplished.

‘‘The photograph isn’t what was photog­raphed, it’s something else,’’ Garry Winogrand once said. ‘‘It’s about transformation.’’ The photographic image is a fiction created by a combination of lenses, cameras, film, pixels, color (or its absence), time of day, season. When I’m moved by something, I want to literally put myself in its place, the better to understand what was transformed. This interests me as a writer and as a photographer: how do raw materials become something else, something worth keeping? ‘‘Those four guys just came from nowhere, and went to nowhere,’’ Burri said of the men in his photograph. The photograph he made of them came from nowhere and went everywhere. My seeing his point of view and taking a picture from the same spot 55 years later did not solve the mystery. But in discovering all that can be known about a work of art, what cannot be known is honored even more. We come right up to the edge, and can go no farther.