The Prince Hotel is not for the weak of stomach. Rooms go for thirty-five dollars a night, ten dollars extra to have someone stay with you. The green-carpeted stairs are littered with crushed cigarette butts; the smell of spilled beer and urine lingers in the halls. Linda and I are sitting on two ugly plastic chairs in an upstairs room of the hotel, laughing over the nosy questions I am asking her. She has worked here, and in all the other flophouses in the Mission District.

It is late afternoon; she is my fifth interview of the day, third prostitute. Sex workers always make for long interviews because their answers are so detailed: How many men in the last month? In the last six months? In the last five years? How many times with each one? Did you use condoms? My hand is tired from writing.

I work for an urban health research project, interviewing addicts, many of whom are prostitutes, about intimate aspects of their lives: whether they share needles, how many times they reuse a needle, what kinds of sex they have, whether they use condoms, whether they use the needle-exchange program, and so on. They answer our questions and listen to our counseling about safer sex and safer shooting techniques; in return, they get an HIV test and fifteen dollars — which is probably immediately converted into drugs. For our part, the head researcher gets more grant money to continue the project, and we street-level researchers get to keep our jobs. Everybody wins.

I sound cynical, but I’m not. I think we’re one of the more effective programs around because we go to where people live, and take them as they are. We don’t preach, but if an addict says she wants to get clean, we’ll refer her to a treatment program. We’re not some kind of cure-all. We offer a straightforward exchange, giving information and money in return for answers to our questions. In the process, we get to witness people’s lives.

I’m well suited to the work because I’m curious about people. No, worse than that, I’m avid. It’s like there’s some secret about life that I never learned as a child, and I keep waiting for someone to come along and tell me. What I get are fragments; in this shattered world, each of us carries around our own tiny piece of the truth. Still, I feel a rush of excitement every time I sit down with a new respondent, because it’s another chance to see into a dark corner of someone else’s life, and, in some oblique way, to shed a little light on my own.

And it’s not cynicism that makes me sometimes feel like a prostitute myself as I wait for respondents, then escort them through the iron security grille of the Prince Hotel and upstairs to a room, where we sit down and try to establish a rapport. When you think about it, there are interesting parallels between social work and sex work. Both are generally considered women’s professions (although men occupy them, too). Both require a way with people, the ability to assess their needs and speak to them in language they can understand. And both deal with the underbelly of life — loneliness, lust, survival. Like my subjects, I’m not receiving benefits or racking up a pension, although I hope they make more than the $12.50 an hour I get. Of course, it really doesn’t matter how much they make, because whatever money they earn goes into their arm or up their nose — work becomes cash becomes drugs in a seamless alchemical flow. The women I interview are often shocked when we add up what they earn in a month.

“Let’s see,” I say, “one hundred dollars a day times thirty days is three thousand dollars a month. Do you work every day? That makes thirty-six thousand a year, without taxes.”

I could live well on that amount of money, I think, maybe even afford a child, but I don’t say this out loud. I just watch them react. Some laugh uproariously; others get tears in their eyes. Once, a thin blonde in a fake mink told me she made three hundred a day, which is a lot for a thirty-five-year-old, but she said she’d do whatever the guy wanted — anal sex, sadomasochism, anything. We did the math together: over a hundred thousand dollars a year, and she was broke and homeless.

Linda, the woman I am interviewing today, has saucy green eyes, a pouty lower lip, and tousled brown bangs that keep falling into her heart-shaped face. I like her sharp sense of humor. When the question of orientation comes up, she says she’s bisexual, but lets only women go down on her “because men don’t know what they’re doing.” She winks at me when she says this, and sips her beer. She’s from a Latin American country, the type of place where children learn to dance before they can walk. She has a great body; I noticed while following her round little hips up the stairs. Even after two kids and years of drug and alcohol abuse, she carries herself like a gymnast. She’s in her early thirties, about five years younger than I am, and has been around. She’s been hospitalized a few times with fractures (courtesy of her boyfriend), liver problems (from hepatitis and drinking), and abscesses (where she shoots up). She’s worn out the antecubital vein in the crook of her arm and is now shooting wherever she can. Her hands are covered with black-and-blue marks. Still, she’s pretty, although it can’t last too much longer if she keeps on this way. But for now she retains a certain grace about her: the sexy smudge of makeup on her eyelids; her throaty laugh; the seductive way she has of leaning forward to draw you in.

And she is sad. I am used to sad on this job. Every day I hear about the horrible things people do to themselves and to each other. Once, a prostitute told me she gave two cops blow jobs in exchange for letting her go; ten minutes later they came back and booked her anyway, laughing. A woman told me she became infected with HIV because her husband secretly stole the clean needles she got from the needle-exchange program and sold them on the street for a two-buck rock of crack. A scared little speed freak who’d been in and out of jail and prison since he was a boy told me he avoided shelters and slept in the park because he couldn’t stand to have walls around him. A woman told me she’d been injecting heroin since she was eleven years old; I spent a long time thinking about that one, about the soft, smooth skin on a child’s inner arm. How could an eleven-year-old stick a needle into her veins? Someone else, some older person, must have fixed her that first time — and then kept her supplied.

This is what I have learned to do with the sadness: pray and let it go. I pray on the subway going home, in the train filled with commuters — just sit there with my eyes closed, breathing in and out. I let each person I’ve encountered that day float into my heart, where I embrace them and then let them go. Rapid transit is my temple; it maketh me sit down with no phones ringing; it leadeth me through the noise and whoosh of the city of death. If I didn’t do my little rush-hour ritual, I wouldn’t last at this job — and, frankly, I need the work. I’m facing a divorce, and still recovering my bearings. In one dizzying year I have plummeted from the privileged, waiting-for-the-right-moment-to-have-kids wife of a businessman to a single woman with a dependent cat and no health insurance. So I need these addicts as much as — or more than — they need me, and not just for the paycheck, but for the reality check: yes, my life is hard, but not as hard as some; painful things happen, but people do survive them, and I will, too.

I try to explain this to friends who think I’m racking up goodness points by doing social work. Lately, I’ve become all too intimate with the ways I’m not good. In the last years of my marriage, I saw how closed I was, how I clung to security, how I was willing to bargain for love, or even the illusion of love. I saw what a junkie I was, convinced I couldn’t survive without a quick fix of my husband’s energy in place of my own, without the security of his warm hand in mine. I saw how little I trusted goodness, my own or anyone else’s; how little I trusted life.

So: this day, this particular prostitute, Linda. I’ve taken down the essential facts: how many sex partners, how many times, condoms, needles, all that. Now she is talking about her children, who are living neither with her nor with their fathers. She occasionally gets to see the younger one, Michael, who is three years old and in foster care.

“The thing about Michael is . . .” She bites her lip and leans back in her chair.

This is not part of the interview. I don’t have to hear it. But I keep still and let her finish.

“He’s a crack baby,” she says, taking a deep draw from a beer in a brown paper bag — but she isn’t drunk. “I was strung out on crack the whole time I was pregnant with him,” she continues. “I was drinking then, too. A lot. I was drinking some when I had my daughter, but I wasn’t on crack. My daughter’s OK. She’s fourteen now. But Michael . . .”

Pain floats across her face like fish dynamited up from the depths. Before, I was riveted, but now I have to look away. Late-afternoon light is streaming in the window and falling in broken shafts on the battered mattress and cracked linoleum.

It’s rare for an addict — for anyone, really, but especially for an addict — to be able to see and admit what they have done to hurt another person. Most of us are more comfortable dwelling on what other people have done to hurt us, forgetting the havoc we’ve wreaked. But Linda is sitting right in the middle of the fire and not letting herself jump out. She is reciting the litany that runs through her head each day, allowing me to hear it.

“Michael is a crack baby. He will never be normal. His foster parents don’t even know if they’ll keep him. He has these tantrums. . . .”

Michael is a crack baby. The sentence encompasses an entire world. There is no going back to the time when Michael might have been anything else. It’s good she’s saying this, I tell myself. She needs to say it. But I want to run out of the room. I want to take this beautiful woman’s hand and turn back the clock for both of us. I see her as a broken child herself. We sit here for a moment, two women.

“I’m sorry,” I say, finally, and she nods. Neither of us cries. My own two aborted pregnancies come to mind. It was never the right time to bring a child into this world; it was too much responsibility. But Linda has done it, and done it badly, done the unforgivable — damaged her own child. How could you? I think. But then, what mother doesn’t? The only other choices are do it perfectly, or don’t do it at all. And how can you make any choice when you’re not in control of your own life? How can you deal with this awesome female power to create new life among the garbage and broken glass of old mistakes?

She is destroying herself, too, that beautiful, lithe body, and she knows it. “I wanted to be a dancer when I was a little girl,” she tells me, gesturing to her crossed legs.

I lean forward, half holding my breath, waiting desperately for her to tell me something good about herself. Tell me one good thing you did, I think, so that I can write it down. I don’t need her to be Mother Teresa; I just need her to round out her story with some unselfish gesture, to balance the meanness and damage. I need it the way a melody line needs the right chord to complete it.

I don’t get what I wanted. She walks away with her fifteen dollars, leaving the unfinished music hanging in the air behind her.

Sometimes in my work I go deep-sea diving after the glitter of what seems like wisdom, and emerge with clogged sinuses and a piece of colored glass.

Sometimes I’m afraid that I work with addicts because it allows me to experience vicariously the dark dramas I resist in myself. I am using them, a friend once said; I’m a vulture. And he was right. Sometimes I fear that I’m a fraud, that I’m only acting out of pity, or trying to ward off evil by doing good. But this thing I felt, waiting for Linda to tell me something good about herself, was different: I was waiting the way one would wait to see a drowning person fished out of the ocean draw that first terrible breath. I needed it for her. I needed it for myself.