A mother's fight for her son on Kensington Avenue | Mike Newall

Aaron left the Chester rehab center the day before Halloween and began the most grueling walk of his life.

Nearly 20 miles away was the place where he said he felt free. Where the heroin made him feel normal. Where he decided he would live now. On the streets.

He called his mother — he had misplaced his ID — and at first Sandra Steinmetz didn't recognize his voice. He didn't call again. And she didn't sleep. She cried, she screamed, she watched the nightly news. She watched an item about a body found in the Schuylkill and called police. She waited for the phone to ring.

When it didn't, she knew her son had to be alive. And she knew where he had to be. So she drove to the avenue.

At first, Sandra was scared — scared of Kensington Avenue, of confronting the misery there and of the reality of where her youngest son's addiction had pulled him. She slid into that reality in steps.

For years she'd been fighting for Aaron, writing down every step of his battle in careful cursive on yellow legal pads — every victory, every setback. But his addiction was still so alien to her. The avenue overwhelmed.

In the summer, she'd driven him down there and waited as he bought heroin. Back then, he'd been sleeping on her deck. His stepfather, Harry, had a rule: no drugs in the house. Aaron said he liked it outside.

Driving Aaron to buy heroin was safer, Sandra told herself, than letting him walk from their home in Pennypack Park. Sometimes if she didn't drive him, he could disappear for days.

In October, after he'd been gone for days, she drove back to the avenue. From the Walgreens parking lot at Kensington and Allegheny, she scanned the street through binoculars. Then, she drove farther in, past the El stops where crowds of young people in addiction descended, under the bridges where small cities of addiction swelled.

She screamed and cried in the car until a man knocked on the window and asked if she was OK.

No, she told him. This is a living hell. And my son is here.

Her son, who was 28, had always been shy and sensitive. He rarely had more than one friend at a time, even as he excelled at Father Judge High School, won a scholarship to college, then worked as an EMT. His singing voice was a blessing. His memory was so acute it was almost a parlor trick — he could recite songs and sports rosters and practically whole movies verbatim. That meant he also recalled every slight, every embarrassment, every low moment in vivid detail. They haunted him.

Aaron was fighting the kind of things he couldn't battle on his own, and his family was doing its best to help.

And now Sandra, who had long worked in information systems for the Archdiocese of Philadelphia, was driving down the avenue in her station wagon, seeing so many lost kids, wondering how we ever let it get this way.

Her husband went with her sometimes. And when Harry, an Environmental Protection Agency investigator, couldn't, she brought their coonhound, Laddie Boy, and they walked side streets. They'd go past the beautiful old McPherson Square library and the police officers who stood outside to make sure no one used on the lawn.

At home, when Sandra would scream and cry without warning, Laddie Boy grew tense. When Harry walked through the front door, he would hug his wife and hold her.

Harry worried that she was starting to get used to the avenue. She worried her heart was closing.

Sandra started talking to young people under the bridges. They'd look at Aaron's photo and tell her whether they might have seen him. They would keep an eye out, they'd tell her. And they'd share their own stories — how they didn't want to be there, how it wasn't a matter of choice. She could see that was true. In their suffering, she could see the power and pull of the drug. One day, under the Lehigh Avenue bridge, a woman overdosed in front of her.

She talked to a woman named Valerie, who had spent the summer in an abandoned church in the neighborhood before going home to her mother and sister. She had been doing well. But the hours alone, when her mom was at work and her sister at school, the avenue pulled at her. And so she made that long trip back, and now she was sleeping under a bridge and talking about shame.

Valerie hugged Sandra, who now better understood what made Aaron take that grueling walk.

Three weeks into the search, this was their regular routine: A lap around the avenue and a few hours waiting around in the needle exchange, where Aaron had been spotted.

Sandra and Harry sat in hard chairs. Sandra watched the faces — as many as 300 on a normal afternoon. White, black, young, old, some clearly new to the avenue, some nearly lost to it. So many with backpacks that held all they had left. "It doesn't discriminate," Sandra said. She chattered to calm her nerves.

An outreach worker, Miss Nance, came over. She took Aaron's picture, promising to distribute it citywide. Outside, a volunteer called a man's name. A rare detox bed had opened, and now she was trying to find him before it filled again.

An old man sat down next to Sandra and Harry. She would remember him later as a soothsayer. "You'll find him," he said, then he left.

Waiting there, Sandra thought of the despair she'd seen in the last three weeks, and felt, unexpectedly, hope. Hope in Miss Nance and the volunteers at the needle exchange. Hope in the young people under the bridge, who had tried to help her in her search and who, she thought, really wanted someone to be looking for them. Hope that, if she'd been brought to her knees by the suffering she'd seen, then the city would fall to its knees, too. That they would fix this horror.

Then Aaron walked in the door.

And Sandra leaped across the room, and hugged him as if a hug could fix everything. She told him she wouldn't let him go. But soon he was out the door again.

Canada. That was the carrot she was dangling for Aaron, in the Dunkin' Donuts on Aramingo Avenue, where he agreed to meet her. They had family in Toronto, who would take him in for a while. Time away from the avenue — that was the most important thing.

Aaron had been through the treatment system here, and still he was on the street. If he was going to relapse, Sandra wanted it to be in a place where he'd have less chance of dying. She knew there were safe-injection sites in Canada.

In the doughnut shop, Aaron told her about his life on the street. How he slept on a blanket in front of a mattress store. Among the people he met, he felt a camaraderie. He wasn't ready to come home.

Sandra kept coming back, with blankets, and apples, and long johns, and Fig Newtons.

One day, she got him to come home with her. He detoxed on the old leather couch in the family room. Sandra never left his side. She walked softly. He got sick from the withdrawal; she got sick from the stress.

Some days Aaron seemed happy, reciting his favorite movie scenes, singing the Beatles tune "When I'm Sixty-four." Some days he despaired, talking of things no parents ever want to hear, seeing no future beyond the avenue.

But there were small miracles. Like when Sandra stared down a man in her driveway until he left, and found Aaron pacing the backyard in frustration the next morning. The man in the driveway, she suspected, had been a dealer, and she had scared him off before he could throw a bag of heroin into the yard for Aaron. A bag that could have killed her son, despite all her efforts.

Two nights before they were scheduled to leave for Canada, Aaron was anxious. He came up from the basement and said he wanted to take a walk, alone. And he did.

He was gone for so long. Harry and Sandra stationed themselves by the door. And Sandra worried that she would have to start her search anew.

And then Aaron walked in the door.

On Saturday they drove together to Toronto.

Maybe, she said, it will be better for him there.