"Nini, my sister begins on the other end of the phone.

She is hesitating. I can tell immediately that she needs something.

"You know I wouldn't ask you if I didn't really need it."

Her voice is unsure. She pauses. She doesn't want to beg.

"But . . ." she begins to say.

I know exactly what she will say before she says it.

The But is the key.

The But hangs there somewhere between yesterday and tomorrow. Somewhere between where I live in Maryland and where she lives in the Midwest, somewhere between my middle-classness and her working poverty, somewhere between two sisters, one who made it to the other side of being poor and one who is stuck in its cesspool.

My sister doesn't really need to explain. I know what the But holds. The But has pockets.

She says it anyway.

"But . . . I really need $258.12. I'm behind on my rent. Can you send it? I promise . . . And you know I go to church. I promise. And you know I wouldn't ask you if I didn't really need it . . . I get paid on the 18th. I'll pay you back. I promise."

I cradle the phone, sitting on my plush pile carpeting in my brand-new suburban house in a spare bedroom that I don't really need. I know she will never be able to pay me back. I know that she doesn't make that much money, and I know she is asking me because she is in a bind. We have been here before and will undoubtedly be here again.

I pause. Not wanting to say no to a sister who has tried so hard just to make it, who has moved from low-paying job to low-paying job in a town where there are few places for a black woman with three kids to go. She is two years older than me, the second oldest, the girl/woman with whom I shared my childhood dreams as we sat cross-legged playing with our dolls and talking about what we were going to be when we grew up. She didn't know what she wanted to be. I knew I wanted to go to college at least. And I wanted to move far, far away.

I think about the conversation I had with my grandmother, whom I called one day after failing to get through to my sister. The operator's recording had told me I had reached a disconnected or out-of-service number: "If you feel you have reached this recording in error, please check the number and try your call again."

I didn't need to check the number and try the call again. I knew I had dialed the right number. It was just the wrong time of the month. This was just one of those bills that my sister couldn't pay.

"You know, Nini," my grandmother told me that day, "she isn't doing so well. She never has any money. Her phone got cut off."

My sister is stuck in poverty. I, on the other hand, somehow got out.

I am what sociologists call "first-generation black middle class." To me that term doesn't mean anything other than someone who is one step out of poverty and two paychecks from being broke. I have income but not true wealth.

My story is not one of those poor-black-ghetto-girl-makes-good stories. I didn't grow up in a ghetto, but I was poor. Not dirt poor like the kind that you read about in fairy tales or novels where the people can't get enough to eat and don't have enough clothes to wear. Not poor enough to qualify for food stamps. Not poor enough to live in public housing. Not poor enough for government cheese or that chicken that came in the can.

We were poor in a different sense, the kind that doesn't slap you in the face until much later when you grow up and realize just how much there was to have and how much you didn't have but didn't know it.

I didn't know that I had grown up "relatively" poor until I became a reporter covering education and someone told me that qualification for free or reduced-price lunches -- the ones I ate at school for years -- was an official indicator of poverty.

I remember going to a news conference once and listening to a member of Congress talk about the need to do away with Head Start because the preschool program for poor children was not successful. I thought to myself, "Oh. I was in Head Start." In fact, when I was little, I thought the name for preschool was Head Start. I had no shame in going to the school where I colored and drew pictures and learned to read before I started "real" school.

Now my three sisters and I are grown. But I am the one shadowed by guilt. It is the same guilt that many middle-class black people have about their success and the lack of upward mobility among some of their relatives. It's about making it and figuring out how much responsibility we owe to family who didn't make it. It's about choosing between taking a trip to Europe and keeping a sister from getting evicted. It is a story about why me? Why did I make it and not my sisters? I was not the cleverest, nor the prettiest, nor the most assertive.

Because it may be impossible to answer the why, perhaps it is best to dissect the how.

I grew up on the "black side of town" in a little white frame house. It had the basic necessities: a front door, a living room (but no dining room), a kitchen, a back door, one bathroom, two bedrooms and a basement. When my parents bought the house in the early 1970s, it cost $7,000. We did without the things we never knew we needed -- things like foyers and walk-in closets and family rooms and garages. Of course, I didn't even know what a foyer was.

Of the two bedrooms, the larger one belonged to my mother after my parents divorced. The other belonged to my three sisters and me. It had one bed -- actually a king-size headboard with two twin-size mattresses pushed together. The last one in the bed slept in the crack between the two mattresses.

The house was immaculate. A speck of lint on the carpet did not go unnoticed. My mother loved a clean house perfumed with the smell of Pine-Sol, Lemon Pledge and Windex. The house could not just look clean, it had to feel clean, smell clean. There were no half-steps. No languid moments to sit and think. Only the constant motion of cleaning was allowed. When Mom's car pulled up in the driveway after work, we'd hop up from in front of the television and clean what was already clean and polish what was already polished. After her hard day's work at the factory, that was the least we could do.

Depending on how far the day of the week was from payday, sometimes we had mayonnaise sandwiches, and bowls of cereal without milk, and Kool-Aid without sugar or sugar water without Kool-Aid. The temporarily empty refrigerator didn't mean we were poor. It just meant we were broke, or more exactly my mother was broke. Eventually, after payday, we would go to the store and get the bologna for the mayonnaise sandwiches, the milk for the cereal and have Kool-Aid and sugar at the same time.

There were spans of pure joy in growing up there. The house was full of song:

"It's a family affair . . ." Sly and the Family Stone sang from the eight-track. "One child grows up to be somebody that just loves to learn. And the other child grows up to be . . ."

We wore halter tops and short shorts and danced on the green shag carpeting and sat near but not on the red crushed-velvet sofa covered in gold roses and plastic.

My younger sister and I fought over who would hold my mother's hand while she shopped -- the hand that didn't hold the purse was the best. And we fought over who would sit next to her when she drove. And Sunday dinner at our grandmother's house was a constant.

Who would have thought us poor with a table full of fried corn, macaroni and cheese, buttermilk and corn bread, greens, turkey and dressing that she prepared? We bowed our heads and gave thanks to the Lord and to the hands that prepared it. Hard times waited until at least Tuesday to visit again.

I knew from watching "The Brady Bunch" and "The Young and the Restless" that there was more out there in the world. We were bused to school on the white side of town, where we saw bigger, newer houses, where the little white girls came with lunch boxes or ran home for an afternoon snack. They had everything, it seemed then.

Still, as child, I considered our situation temporary. Someday, my mother would get a better job and a pay raise at the airplane factory where she put together electronic control boards. Someday, I would get a job, too, and buy all that I needed. Poverty, as they say, was a state of mind. It was not my state of mind.

By the time I became a teenager, I was determined to study myself into a better place. I had been labeled gifted and talented and put in accelerated classes. In high school, I took as many honors courses as I could, and competed with and beat the other students in my school who I thought were the smartest. I would do as they did, take the ACT, apply for college. And get out.

People now ask me the impossible question: "How come you didn't grow up to be like your sisters?"

My questioners are sincere -- this question gnaws at me, too. But their ignorance shows in their expectation that I can give a one- or two-sentence answer. These are people, black and white, who have probably always had sugar with their Kool-Aid and bologna with their mayonnaise. So they are often left puzzled.

I wonder what they mean when they say: like your sisters. My sisters were raised to be good people. And I love them.

Sometimes, and only if a questioner appears to have more than a glancing interest, I answer this way: "Maybe it's because our dreams were different. Maybe it's because fate gave me a break. Maybe it's because I made different choices. Maybe it's because my two older sisters absorbed the shock of poverty's blows for me, making room for me to move around them and walk past without bruising."

Truth is, I am more like my sisters than the questioners will ever be able to understand. My clothes, my house, my car, my vacations don't define me. Those things say I am middle-class, but inside I'm still the same little girl who knows what it means to struggle with paying the rent.

I live in a vinyl-sided house with a brick front. My husband and I have two cars in the garage, both used. We have enough groceries in the cupboard. If we stretch it, we can take a vacation to France. I am not complaining or boasting. I'm just explaining. I have something people in my family don't have: I have a regular paycheck, a house, a used Volvo.

I am not rich, though some in my family think I am. Rich is all relative to someone who doesn't have the rent money.

When it was reported that Clarence Thomas had a sister on welfare, a lot of black people nodded and understood. Thomas had said that his sister was an example of welfare dependency. You could hear the uh-huhs in beauty salons and barbershops. He got some nerve. Nothin' worse than a black man who don't remember where he came from.

One thing you rarely hear black people do is criticize those in their family who haven't succeeded. We don't make those simple judgments: "Well, if you would just get a job, then everything will be okay." We know there is something more complicated going on that allows some people, even those in the same family, to rise and others to get pulled down by the undercurrent. I know some people are going to say they understand what that undercurrent is: lack of motivation, lack of energy, lack of education.

I always say it ain't never that simple, using the word ain't in its proper cultural context.

Black people understand the overt and covert racism, the collective depression that strangles some of us. And we understand that coming from the same family links you in ways that are infinite. That when a sibling messes up, it is forgiven. At church, when the story of Cain and Abel is told and God asks Cain where his brother is and he answers, "Am I my brother's keeper?" we bow our heads and whisper-shout: "You darned right you your brother's keeper. And your mother's keeper and your father's keeper, and your sister's keeper, and her kids' too."

You may lose your house, your car, your husband, or you may succeed beyond your wildest dreams. Either way, you'll always have your family.

After my parents divorced, and my father moved away, my mother got up before daybreak every morning, ironed her jeans and a white blouse, climbed in her old Ford Granada and drove to the airplane factory. There, she punched a clock and worked on the control boards for eight hours, leaving her station only for 15-minute breaks and lunch. I didn't think about it then, but it must have bored her. She was a fiercely intelligent woman -- but her life didn't take her anywhere. And intelligence didn't keep her from making mistakes.

She was born in Mississippi, and like so many other black people from the South, she rode the train to Chicago, part of the Great Migration north. My grandmother had to work a lot. It was a hard childhood. "We had to raise ourselves," is all my mother says about it.

My mother had dreams of doing better. I know because she would pour them into my ear: "You know, Nini, I want you to go to college. I always wanted to be in a marching band in college. Maybe you could be in a marching band."

I felt like a pebble being pushed along a stream, tumbling along, somehow never taking the wrong turn. Instead of hitting boulders in the stream, I somehow caught a current that went around them. I was a lucky pebble.

My sisters, though, got caught under the boulders.

My oldest sister had a child when she was 16. She said she had a baby with a boyfriend because her friends were having babies. I remember coming home on the school bus and seeing her standing in the door of our house. She wore a nightclub-red nightgown and carried a full belly. The kids on the bus teased me, saying my sister was going to have a baby. I vowed silently then I would not be like her.

My next oldest sister went off to college before I did, but quit in her sophomore year when she didn't make the grades and returned home to a menial job. My mother didn't seem too disappointed at the time. She just said schooling was harder for some people.

I focused on going to college, getting a job, a job to which I would carry a briefcase and wouldn't have to wear a uniform.

The current took me elsewhere.

It is a beautiful spring day in Washington. My oldest sister and my mother have come for a visit. I pick them up at the airport and we dump all the luggage in the trunk of my Volvo. My mother gets in the front passenger seat and my sister slides into the back. My sister is 39 and this is her first airplane ride in more than 30 years.

She is excited in a childlike way about the flight. She talks about the peanuts they served on the plane, and about not being able to sleep because of the bumpy ride and her fear of flying over water. She is on the ground now and she is happy. The trip has taken her away from her troubles -- temporarily.

"If you gave me this Volvo," she says almost immediately, "then all my troubles would disappear."

I tell her the bank owns the Volvo. And I am reminded of the gulf between us. She doesn't have a car anymore. She is hungry. She hasn't seen Washington before. She hasn't seen Baltimore. I take them to a restaurant on the waterfront and tell them to order anything they'd like. She doesn't want any exotic Thai food or Indian food. She wants something she can recognize: preferably fast food, preferably a chain.

I urge her to try something new, to branch out. Try this, I tell her, coaxing her to try my tandoori chicken pizza. She tastes it, with its chutney, and finds it gross.

Later, after she has settled into one of the guest rooms and unpacked her bags, I tell her about my work, and find a way to bring up this question that has been nagging at me: "How did our lives end up to be so different?"

She tells me her childhood was different from mine. Then she begins to talk about her secrets, the things that happened to her. The reasons she skipped school. The reasons she dropped out of school. The friends she hung out with. The reasons she ran the streets, as my mother put it.

Then my oldest sister tells me something she has told no one else. She says that at a time when my mother wasn't looking, a man pulled her aside and abused her. And continued to abuse her for years. It became a secret and it eventually made her lose her mind.

"I got molested. It's always been inside of me . . . I hate to wake up in the morning."

It takes my breath away to hear this secret. But it can't hurt me as much as it hurts her. I know that and I wonder, where was I and why didn't I know what happened to her?

I tell her that she is not too old to put herself together. I drive her to the vast, affluent, majority-black neighborhoods of Prince George's County and tell her that black people live in these houses. Look at the cars they drive. They have good jobs. You could have this, too.

She smiles. "I always wanted to come up here and see how good you were doing," she says. "I want a house. I want a man that works. I want somebody to listen to me. I want to clean my body out, but it's not going to clean my mind out."

She looks around my house, at all the unnecessary stuff I have accumulated. "Don't you think I want a house like this? But now, it's too late."

I tend to disconnect from information in a cold way. As my sister tells her story, I just take it in, without emotion. She talks about being told that she was not very smart, being told she was the black sheep of the family. In time, she fulfilled the family's prediction. From her teenage years on she just knew that she would live the same life she had always lived: on the edge of the poverty line.

"I hurt all the time emotionally," she says.

Three months later I get a chance to ask my uncle the same question. He lives in Denver and is a successful lawyer. He is my mother's brother, the middle child. Her baby brother lives under a bridge, temporarily homeless, temporarily unemployed.

In a lot of ways my Denver uncle is like me. He carries the same burden. He, too, made it out. Sometimes he even refuses to go back. I ask what happened.

He tells me my mother is brilliant, perhaps a genius.

A genius? I wonder. The brilliance never showed itself to me except the times when I was a teenager and she knew I hadn't gone bowling, but went instead to the party she forbade me from attending. I thought she was the smartest person in the world and maybe the meanest, too.

He tells me how when they were growing up, it was she who taught him to read, taught him math and whizzed her way through school. But then she got pregnant. I asked what happened to the genius. Pregnancy surely doesn't dull the mind. He tells me she got tripped up by low self-esteem. I still don't understand.

I tell him how I feel when I go back home to visit my family, my own young son in tow, how it haunts me when I see my sisters going two steps ahead and five steps back, how it pains me to see my grandmother's little house, site of so many family gatherings, swelling inside from too much heat and not enough fresh air. It's as if the house holds too many secrets and is about to burst.

I remember sitting on the sofa there one summer night as my oldest sister smoked cigarettes in the glow of a red light bulb she had put in. The room was soaked in red, and I thought then we were all going straight to hell. I think about my grandmother's house now and how it is filled with smoke and how nobody stops anybody from smoking around all the grandbabies.

My uncle tells me he, too, finds the house to be a symbol of something that sucks the life out of people living there.

Long ago he told my grandmother that it was worth nothing and she should sell the place before it fell apart. She told him no. Then she redecorated. She put up wallpaper and new curtains. Bought new carpet and a new sofa. Put on an addition with money she had saved from working as a hospital cook for 30 years. It was like putting new wrapping paper on something that needed to be fixed from the inside out. It looked pretty on the surface, but inside it was falling apart.

But it is a house to which people in my family have all returned when there was nowhere else to go. My grandmother opens her doors, cooks Sunday dinners and they stay as long as it takes to get themselves together.

Sometimes they never leave.

I phone my younger sister one day to see how she is doing. She was the one who took up for me at school. While I read books and went to class, making all A's, she knew what was really happening in the school. When people talked about me as high school girls do, she, with her quick tongue, cut them down.

She is beautiful. Tall, thin, cherry black. Men find her irresistible. She charms them. They fall in love with her. Then, when the relationship or the marriage goes bad, they find they cannot stop loving her. Because she no longer loves them, they want to hurt her. So they find weapons -- the courts and child custody laws -- and they fight her for the children.

She tried to leave town once. She moved to another state with the children, found a new job. One day, when she was at work, a sheriff's deputy went to her son's school. He showed a warrant to the principal that said the boy must be returned. My nephew pleaded with them to allow him to stay until school was out. He needed to walk his younger sister home, the sister who has the same mother but not the same father.

They took him anyway. Now my sister, young but with a full head of salt and pepper, spends all her energy and money petitioning for custody and visitation rights.

One day I ask my mother to answer the question of why her daughters are so different. She talks to me as though she were speaking to an interrogator. She speaks in third person as though she is looking down on her life and is not in it. My mother, it turns out, also spends many of her waking hours thinking about this question and about her girls and their lives and what she did and didn't do. Sometimes she cries because the factory cut her job and, with no money anymore herself, she cannot help her children.

"They all lived with a mother that tried to work. When she stopped working that had an effect on them."

"My oldest daughter is a crackhead. Son living with girl since 15. One daughter pregnant, unmarried. Daughter, 23, has five kids, one deceased."

"My next child works in medical records at a clinic. She has three kids. Joint custody of two. Very religious. Bitter toward her father because he wasn't there for her. He just came into her life when she was 35. High values. Low self-esteem. A loner. I think she gives all her money to her church."

"My third child is married. One with little boy. Finished college. Well educated. Well-paid job. Successful. Bitter about childhood."

"My youngest daughter is working for the school board. She lost custody of one of her children. She is bitter. Unhappy."

It's not an answer, but it's all she's got. "You are the one that minded. You never talked back and didn't have to have much discipline. You were more respectful. You were a good seed . . ."

So now I look back and I can see some of the rocks that my sisters hit in those streams: the men, the abuse, the drugs, the lack of dreams. They can probably see those rocks, too. Everybody has better vision when they are looking back.

I can see it clearly as I sit in my spare room -- the one that I don't need -- and cradle the phone in my ear.

And pray that my husband, who was born into the black middle class, whose mother and father both have doctorates, will understand. My husband, whose father is a wealthy businessman and comes from a long line of well-educated middle-class black people. Whose paternal great-grandfather was a college president and great-great-grandfather was summoned by Booker T. Washington to teach philosophy at a historically black college.

As I sit there, I know my husband has never dealt with a request like the one on the other end of the phone line. When I tell him, he seems baffled. He doesn't feel the pulls and tugs that that will forever bind me to two classes, the middle-class side where I am now and the other side where I grew up and where my mother and sisters still live.

I cradle the phone again and listen as my sister, the second oldest, tells me how she got so far behind that she couldn't pay her rent. She doesn't need to explain any more. I know her life all too well. As she talks, I open the file cabinet and pull out the checkbook for the account I jokingly refer to as my family trust fund.

I lift the worn, thin, blue plastic cover. The balance is dwindling. I look at the withdrawals that have been made in 13 years.

$300 to keep my mother's phone from being cut off.

$150 to keep my oldest sister from being evicted.

$240 to pay my mother's mortgage.

$169 to pay my mother's property taxes.

$50 to my mother just because.

$250 to pay for the funeral clothes of a baby niece who died of sudden infant death syndrome.

I flip through the ledger and find a clean check. With a blue ballpoint pen, I make a check out for two hundred fifty-eight dollars and 12/100. And I sign it. And I put it in an envelope. And I seal it shut.

And I know that it will never come my way again.

I am my sisters' keeper.

DeNeen L. Brown is a writer for the Style section.