One morning in Paris, I stopped by the apartment of Pérola Milman, a quantum physicist who lost her husband, Ivan, in the crash. Milman is a lean, athletic woman, originally from Brazil, with warm caramel skin and an aquiline nose. We sat facing each other in the living room while her children played nearby. Before the crash, Pérola and Ivan dreamed of moving into the city. After the crash, she finally made the move without him.

“I couldn’t stay at our house anymore,” she said “ I couldn’t do it. I had to move on. So I just left. I left all my furniture there. All my clothes. Everything. I had to do it.” She turned her head to watch the kids, then she said: “Children are amazing, you know? A psychologist told us after the accident that children do not have a sense of death until they are 6 or 7. And I radically contest this. When it happened, Jose was 4 years old. And of course, it’s a conversation I will never forget. I told him, ‘Listen, there was an accident with Daddy’s plane, and he’s not coming home.’ And he started crying as I never saw him cry before. He was saying, ‘But there are so many things I wanted to make for him.’ ”

Milman’s eyes were wet, but she went on. “I am a scientist. I know something concrete happened to the airplane. But I cannot prevent wanting the mystery. I don’t want them to bring up the bodies. I don’t want all that coming to the surface. I have this need to turn the page. It’s very strange to think that this place exists somewhere and my husband is there, in the same clothes he was wearing the last time I saw him, and his ring . . . and his necklace. . . .” Her voice trailed off, and she smiled.

The next day, I visited the apartment of John Clemes, whose brother, Brad, had flown to Rio on the airplane that would become Flight 447, which he reboarded when he discovered that he could not enter without a visa. After the accident, Clemes and Milman became friends, but the question of whether to bring up the dead hovered between them. As deeply as Milman felt the need to leave her husband below, Clemes felt an obligation to bring his brother home. “It’s horrible thinking they’re lost,” he told me. “There’s no body, no saying goodbye, it’s just . . . gone. For the first couple weeks, I just assumed they were going to find the plane. It wasn’t imaginable that they weren’t.”

Before the announcement from the Alucia last month, these differences could be set aside, distant and immaterial, but the discovery made them manifest. After less than 24 hours, the French minister of ecology and transportation, Nathalie Kosciusko-Morizet, pronounced on television, “These bodies will be raised and will be identified.” But whether that promise is possible to keep remains unknown. Now that the B.E.A. has recovered the black box cylinders, its crew will try to bring up at least one body, using the same claw-and-basket system. Forensic experts say this is dangerous and tricky. After two years, the bodies may be recoverable, but they will have a soft, fragile consistency that is likely to disintegrate in the robotic claw. Some experts say that the bodies should have been photographed exhaustively by 3D cameras before the recovery of the black boxes began. Already, the process of scouring the wreckage may have kicked up turmoil on the bottom.

Even if the bodies can be recovered, the question of whether they should be recovered remains difficult to answer. In the end, the decision is binary: either all the bodies will be recovered or they will all be left below. But this is a choice that could not have existed even a decade ago; it is one that could emerge only in the strange confluences of Flight 447. Because the plane was used so widely that its disappearance had to be explained. Because the only way to explain was by recovering the black box — an archaic device on its way to obsolescence but not there yet. Because the tools and technology to locate those boxes in the depths of the midocean ridge were available for the first time. And so, in order to solve the mechanical mystery, the closure for families would have to wait. They would have to wonder once again if their mothers and brothers and sisters were coming home. They would have to struggle with the possibility, each family alone, torn now among themselves, and sometimes even torn within.

Stepping off an airplane in Brazil one afternoon, I noticed an e-mail marked urgent from Mary Miley, whose sister, Anne DeBaillon Harris, was on the plane with her husband, Mike, headed for two weeks in Paris. Anne and Mike were the only Americans onboard, and I had spoken with Miley perhaps a dozen times, sometimes for more than two hours. Something about Anne kept pulling me back. I would like to say that it was her eyes or her smile or some detail from the photos I saw of her, but Miley’s stories of her sister were not so nostalgic. She described Anne’s fight with cancer in her 20s, the ministroke on her left side, the migraines and bouts of fibromyalgia that would seize her for days on end. But I also heard from Anne’s friends, about how in Rio many of these problems seemed to fade, at least enough to give Anne, a girl from Lafayette, La., the taste of a life unlike anything she’d known, bustling through metropolitan markets, haggling with street vendors and learning to samba. I found myself exploring her neighborhood in Rio and driving into the hills west of town to stand at the edge of a terrace bar where she liked to sit with friends in the evening, gazing over the beach as waves crashed on the rocks below. And always, I would check back with Miley to share what I had seen and heard — and to ask more questions about Anne.