On May 5th, just after midnight, a Honduran woman named Ana Rivera and her five-year-old son, Jairo, tried to cross the U.S.-Mexico border. They were caught scaling a fence in El Paso, and spent the night in a holding cell at a U.S. Border Patrol station with other mothers and children, a group of about twenty-five people in all. On the afternoon of their second day in detention, two male agents entered the cell. “They didn’t say anything,” Rivera told me. “They just walked over and grabbed Jairo. It felt like my son was stuck to me. He clung to me, cried and screamed. They had to pull him away.” She pleaded with the agents to tell her what was going on. The other women in the cell were too stunned to speak, Rivera told me. In the next few hours, the agents started taking other children, too. Eventually, the mothers were told that they would be reunited with their children after spending a few days in jail.

Nearly six weeks later, Rivera has not seen her son. Shortly after the Border Patrol agents took Jairo, she signed a voluntary-departure order, which fast-tracked her for deportation. She’d been confused, she told me, and thought that signing would allow her to see her son sooner. Instead, she was charged with illegal entry, held for a few days in criminal custody, in New Mexico, and then was sent to an Immigration and Customs Enforcement (ICE) center back in Texas. On Monday, I visited her in a small, unfurnished room with white cinderblock walls at the ICE Processing Center, in El Paso, where she’s now waiting to be deported.

Rivera, who is thirty-seven, wore a standard-issue orange jumpsuit and sneakers without laces. She seemed dazed. The day before her son was taken, she had been informed, after a mandatory physical, that she was two months pregnant. She’s been taking vitamin pills each day, courtesy of ICE. “I don’t care if they deport me,” she said. “What hurts me is my son. I need to be with him.”

During the first twelve days that she spent in federal custody, Rivera had no idea where her son was. She stopped eating, could barely sleep, and cried constantly. “The stress was too much,” she told me. No one could give her any information about her child, and she didn’t have a lawyer to help her press the point. By the time that she arrived at the ICE facility, on May 18th, she’d become so upset that she had trouble speaking.

The Trump Administration has been separating parents and children at the border without any clear plan or protocol to keep track of them while they’re apart. Under its new zero-tolerance policy, parents are criminally prosecuted for illegally entering the U.S. and then are sent to ICE for detention and deportation, while their children, who are treated as though they came to the country alone, go into the custody of the Office of Refugee Resettlement (O.R.R.). “Once the parent and child are apart, they’re on separate legal tracks,” John Sandweg, the former acting head of ICE under President Barack Obama, told the Times. In the last month, the government has separated some twenty-three hundred children from their parents, who have mostly been forced to locate their kids on their own.

One morning late last month, a few days after Rivera was transferred to the ICE facility in El Paso, another inmate—a Guatemalan woman—approached her with an idea. “She saw I was crying, and she said, ‘Here, take this phone number and try calling it,’ ” Rivera said. The woman had been separated from her one-and-a-half-year-old child, and she’d eventually found him with the help of an O.R.R. case manager in Chicago. Rivera didn’t have enough money on her phone card to call, so the Guatemalan woman lent her some. “I called the case manager, and asked if my son was with her,” Rivera told me. “The woman said to me, ‘Thank God it’s you. Jairo is here. I’ve been looking for his mom.’ ”

Rivera began speaking with her son twice a week, for fifteen minutes at a time. When I asked her to elaborate, her face tightened, and she started to cry. “He’s not the same as before,” she said. “He used to be more active, more spirited. Now he’s sad all the time.” Rivera gave the number of the O.R.R. case manager to her mother and older son, who both live in Honduras. They all call Jairo every week. “That way, he’s not alone,” she said.

Rivera has been growing increasingly frantic that she might get deported without him. Two weeks ago, she and nine other women at the El Paso Processing Center who’d also been separated from their children decided to contact a local immigration lawyer named Linda Rivas, the executive director of the Las Americas Immigrant Advocacy Center. Rivas had been coming to the ICE facility to meet with another client, a Guatemalan asylum seeker who’d been separated from her daughter. Rivera and the other women passed along their information to the Guatemalan woman, who relayed it to Rivas.

“Some of these women know where their kids are, some don’t,” Rivas told me. “All of them handle the grief differently. Ana is especially traumatized. She’s pregnant and detained. And she’s just miserable without her child.” Because Rivera had already agreed to voluntary departure, there was little that Rivas could do to help her legally. But she decided to pressure Rivera’s deportation officer at ICE to hold off on deporting her until she could be reunited with her child. “There’s no set policy for how to do this,” Rivas said. “It depends on who the individual deportation officer is and how willing he or she is to coördinate with a case worker at O.R.R.”

A Crisis at the Border More coverage of the Trump Administration’s immigration policy from The New Yorker.

Fortunately, Rivera’s deportation officer seemed receptive. (While ICE granted me access to the facility to interview Rivera, it declined to make her deportation officer available to speak with me.) According to Rivera, Jairo left Chicago last week and was now in an O.R.R. facility near El Paso. She excitedly showed me the phone number of his new case manager—it had an El Paso area code. Knowing that her son was close by lifted her spirits, even if she couldn’t see him. But each call with him was taxing. “I don’t really know anything about him. I mean, I just know what they tell me,” she said. “My son says to me, ‘Mom, come here and take me home. I don’t like this!’ ” Rivera repeats what her deportation officer has said to her: “Be patient.”

When I left the ICE facility, late on Monday afternoon, Rivera seemed to hover between expectancy and gloom. Her eyes darted as she talked. “Why can’t they just put me on a plane with my son?” she said. “That’s all I want. I want them to deport us right away. I want to get out of here fast.” She added, “But I’ve told them, ‘If you take me to the airport and my son isn’t there, you’ll be killing me.’ ” That evening, I received a text message from Rivas, saying that Rivera’s deportation officer was trying to make arrangements to send mother and son home together. “It’s good news,” she said. “And I appreciate that. But until Ana and her son are on that plane together, we still can’t be sure this is happening.”