There's a video store about two blocks from my office where, for the first time recently, I rented tapes -- and joined the movie-rental club. I produced my identification, fished for my fee and was asked by the store manager if I was the person who writes for The Washington Post. Yes, I am, I said. In that case, she answered, I'm your cousin.

And so, it turned out, she was. My great-aunt -- my father's aunt -- had married her grandfather. The two of them, along with my great-aunt's brother, had run a photo studio in Warsaw (the brother had learned photography taking pictures for the German army during World War I). Together, they were the last of my family to leave Poland.

My new cousin said she had a videotape of old family movies. Would I be interested in seeing it? I said I would, and so, within a day, I was sitting in front of my TV looking at old home movies transferred onto videotape. Much of it I found boring. There were some scenes from the 1940s in which I thought I recognized a few faces, one or two that I vaguely recollect peering over the crib at me. Was that a cousin long dead? Could that be my grandfather's sister?

My father's family is something of a mystery to me. My father was an orphan. His mother died of tuberculosis in a New York tenement. His father, poor and (so my aunt insisted) irresponsible, put my father in an orphanage. Shortly thereafter, a Polish policeman's blow that had deafened my grandfather in one ear many years before took its final toll. My father's father was hit in New York by a truck he never heard coming. At the age of 8, my father was alone in the world.

I accelerated the tape. Color footage of weddings and bar mitzvahs skipped by. The locale changed. We were now in the suburbs of Detroit, where some of the family had gone. There were pictures of suburban houses, heavy cars that moved with the assurance of trains. Then, suddenly, the tape reverted to black and white. It was 1932, the Flatbush section of Brooklyn, and there, coming around the corner, were four people. Could it be? I froze the tape on the screen. My heart seemed to stop. Looking straight into the camera, as if at me, was my father, 22 years old and dashing.

I played the tape over and over again. My father was walking. He was smiling. He was holding the hand of my cousin Frederica, then 3 years old. He was standing next to his sister, Rebecca, and her husband, Joe. My father was dressed in a suit and overcoat. It would be seven years before he would meet my mother and two more before my twin sister and I would be born. My father's still alive, but here he was as I had never seen him -- not a man in a snapshot, but a walking, smiling, young human being.

Of course I know that my father was once 22. I know, too, that he was once the age I am now. But what was he like? Were his problems and concerns similar to mine at his age? What could we have said if we talked, man to man, contemporary to contemporary? I thirst for this insight into my father, which is, I understand, a selfish craving for insight into myself. The older I get, the more I think that to really know yourself, you have to know your parents.

The one grandfather I knew as a child, my mother's father, had been a religious scholar in Poland. In America, he went into a relative's plumbing-supply business, but by the time I got to know him even a bit, he was an old man -- old and sick, maybe senile, the victim of a stroke. As a boy, I used to visit him in a nursing home, a sad place reeking of disinfectant. My father would bring him Yiddish magazines and newspapers. He seemed to read them all. Was my grandfather an intellectual? What were his politics? Is it true he tried to abandon his wife and children by not bringing them over from Poland? What's his side of the story?

I have a fantasy. In it, I sit on a stoop with my grandfathers. I ask about their lives, their loves, their aspirations. I look for myself in them -- clues, glimmers. We laugh. We joke. From my mother's father I find out if that sly smile I've seen in photos indicates a sense of humor. Was he as bright as I think he was? Was he, in fact, an intellectual trapped behind the counter of a plumbing-supply store in New Jersey, a Talmudic scholar rushing to the back for pipes and joints, couplings and fittings? Had a fine mind dimmed while fetching toilet seats for the new homes of the new suburbs? Oh, Grandpa, who were you?

I called my father while his image was still frozen on the screen. How did he look? he asked. Handsome, I said. Yes, very handsome. And Rebecca, Joe and Freddy? Joe looked as always -- tall, distinguished, a Ray Milland type. Freddy was as cute as could be. But Rebecca -- Rebecca did not look good. Her face was puffy, her eyes dull. Unlike a snapshot, the film conveyed a certain mood. Yes, my father said, she had been depressed. Depressed? I had not known that about my aunt. What else didn't I know?

My new-found cousin is making a copy of the tape for me. Then I will play it for my parents and my sister, for my cousin Freddy and, over and over, for myself. I regret now that I didn't take films of my family, of my own son, so that someday, when he's interested, he could have seen his father walk toward him as a young man. Someday he, too, may notice that even in -- maybe especially in -- families, what's past is prologue. The videotape proves that. My great-uncle ran a photo shop in Warsaw; my cousin runs a video store in Washington. ::