Playwright Arje Shaw’s first memory was crawling across the floor, finding a piece of black, moldy bread and dipping the crust in water in order to chew it. He was 18 months old. “I looked like a Biafran baby,” he says.

The time was World War II, the place Tashkent, Uzbekistan, where Shaw’s Polish father had settled after fleeing the Nazis. Before emigrating to America, the family spent three years in a displaced persons camp at Bergen-Belsen.

Shaw’s acclaimed play, “The Gathering,” which opens tomorrow at the Wadsworth Theatre, is all about displacement, about the lingering effects of the Holocaust and the effect it has on the relationship between fathers and sons.

The father and son in the play are Gabe (Hal Linden), a Holocaust survivor, and Stuart (Sam Guncler), a speechwriter for President Reagan, who bitterly argue during the course of the play. The source of their conflict is Reagan’s controversial 1985 visit to a Nazi cemetery in Bitburg, Germany.

Like the fictional survivor, Shaw’s father, also named Gabe, was forced to leave his mother and sister behind after Nazi soldiers nearly beat him to death. His crime: failing to wash a truck in a way that could pass the officer’s white-glove test. They perished in the Holocaust.

Ultimately, Gabe made it to New York, packed in the hold of a refugee ship on stormy seas with his wife, his son and a baby daughter. But as the family settled in a sixth-floor walkup at Avenue C and East Seventh Street, 8-year-old Arje sensed his father’s sadness.

“He had that far-off look,” Shaw, 59, recalled. “He never truly mourned his loss. He kept it all inside of him. And his frustration of having to cope with a new language and culture made him volatile and angry. He was so preoccupied with surviving and sacrificing for his family that he wasn’t emotionally available.”Though Shaw felt emotionally abandoned by his father, he could not help but repeat the cycle with his own wife and daughters. While obsessed with the theater since appearing in plays at Bergen-Belsen at age 6, he earned a master’s degree in social work and went to work for Jewish communal organizations to support his family. “But I was angry that I couldn’t be an artist,” he conceded. “I felt very unfulfilled, and my reaction was a defensiveness, a lack of patience.”

The turning point came in 1986, when Shaw, then in his mid-40’s and the executive director of a New Jersey YM-YWHA , decided to stay home one weekend to write a comedy about his wife’s kosher catering business. “You can’t do that,” she joked. “You can’t write, and you’re not funny.” Undeterred, Shaw rose at 3 a.m. every morning to write the play before going off to his day job. Five years later, “A Catered Affair,” co-written with producer George W. George, debuted off-Broadway.

Shaw’s third play, “The Gathering,” also began as a comedy — until the author discovered he was weeping while he wrote. “Every time I sat down, I was mourning my father’s losses and my losses as a child,” said the author, a veteran of men’s consciousness-raising groups. “I wasn’t satisfied with who I was as a person, and a lot of it was because I was not happy with my relationship with my father,” he added of the genesis of the play. “I felt I finally needed to understand how his life was cut out from under him. I felt I needed to emotionally connect with him while he was still alive.”

As Shaw prepared for a 1999 run of his play at Manhattan’s Jewish Repertory Theater, largely financed by a second mortgage on his home, he sent Gabe two drafts of the script. But he was too intimidated to ask whether his father had read them. On opening night, he was more nervous about Gabe’s response than that of the newspaper critics. “The minute the curtain closed, I raced out to the street to smoke,” he recalled. At the post-performance reception, the taciturn octogenarian hardly said a word. “But his face was all lit up. I could see the love,” says Shaw, whose play ran for five successful months at the Jewish Rep.

Today, “The Gathering” is Broadway-bound, but Shaw chooses to keep his day job at the Y. He still rises at 3 a.m. to write, averaging just four hours of sleep a night. But he finally feels validated as an artist and as a son. “With ‘The Gathering,’ I’ve been able to come to closure and healing with my father,” he said. “We’re much more connected. I just feel him loving me.”

“The Gathering” runs Feb. 3-28 at the Wadsworth, 11301 Wilshire Blvd., L.A. For tickets, call (800) 233-3123 or (818) 986-2908 for group rates.