The Holocaust has produced many tales of miraculous survival. But none is more mind-boggling than the story of Berlin’s Jewish Hospital. In the heart of Nazi Germany, as death and destruction rained down on European Jewry, the Jewish hospital remained open for business.

Staffed by Jewish doctors and nurses, and treating Jewish patients, the hospital survived Kristallnacht, survived the “Final Solution” and even survived the destruction of the Third Reich.

Berlin’s Jewish Hospital remains standing to this day. Yet hardly anyone knows a thing about it or its plucky staff that once upon a time saved the last remnant of Berlin’s Jewish community.

Writer Daniel Silver hopes to remedy that with his new book “Refuge in Hell,” a well-researched account of the hospital and its staff. But he has already faced resistance to the story because, frankly, some people don’t believe it.

“I was on a radio show,” says Silver, a former CIA analyst and himself Jewish. “Someone called in and said, ‘How could people have kept this hidden from the Nazis?’ The host thought I was a Holocaust denier.”

Actually, the hospital was never hidden from the Nazis. Adolph Eichmann visited the facility often, and even overrode orders to close it down.

Like others, Silver was dumbstruck when he learned of the hospital’s existence several years ago. “My first reaction was incredulity,” says the Washington, D.C.,-based writer. “It didn’t compute. It seemed entirely inconsistent with what I knew about how the Nazis treated Jews.”

Silver began informal research, finding out who was still alive, who wasn’t, and what studies had been done about the hospital. Hardly any, it turned out.

Three years ago, after Silver retired from his law practice, he turned his attention toward writing a book about the hospital. “I kept wondering,” he says, “what would it have been like to live as a Jew under those circumstances.”

As he learned from interviews with survivors, those circumstances were strange indeed.

Under the leadership of an enigmatic Prussian Jew, Dr. Walter Lustig, hospital personnel made the most of an ever-worsening situation.

Once a top Berlin facility, the hospital gradually became a clearinghouse for Jews facing transport to the camps. The Nazis, in their weird way, wanted the Jews healthy before sending them off to die.

As the noose tightened, staffers and patients were routinely shipped off.

Yet somehow life went on. Sexual affairs flourished between doctors and staff. Frequently, nurses courted death by going into town — sans the ubiquitous yellow star — to catch a movie or have their hair done.

Says Silver: “Figuring they had no future, they grabbed whatever pleasure they could.”

The hospital’s survival was not a matter of luck. Because so many patients and staff came from mixed backgrounds, the Nazis hesitated to fully enforce anti-Jewish laws, with their Byzantine qualifications for people of “mixed race.” They didn’t want to enrage “Aryan” relatives too much, at least not until the war had ended in Germany’s favor.

That provided enough of a loophole. When a wing was turned into a Wermacht infirmary, the hospital was guaranteed electricity throughout the war, even when the rest of Berlin went dark.

Of all of the characters in the book, Lustig proves the most fascinating. To some, he is a villainous collaborator; to others, a prickly saint who worked to save lives. Silver sees a middle path. “He was not likeable, but that doesn’t mean he wasn’t capable of some degree of heroism.”

He didn’t get much of a reward. At war’s end, Lustig was taken away by Russian soldiers and summarily shot.

Silver was in many ways the right person for this project. Growing up in Berkeley, he and his family belonged to Congregation Beth El and Temple Beth Abraham. He went on to attend U.C. Berkeley, earned a doctorate in anthropology at Harvard and later a law degree.

He settled in Washington, D.C., to work for an international law firm, Silver then served as general counsel for the National Security Agency before entering private law practice.

“All my life experiences helped me do this,” he says. “My training as lawyer and social scientist helped me deal with historical fact in an methodical fashion.”

As clinical as that sounds, Silver was actually moved by the courage and tenacity of the Jewish Hospital staff. “I learned a lot about the human spirit,” he says. “These people lived through the Nazi horror, knowing at any moment they could be carted off to a death camp, and yet came through without any apparent psychological scars, and had the strength to rebuild their lives.”

“Refuge in Hell” by Daniel B. Silver (311 pages, Houghton Mifflin Co., $24).