“The Book of Aron” by Jim Shepard. (Knopf)

In the summer of 1942, German soldiers expelled almost 200 starving children from an orphanage in the Warsaw Ghetto and packed them into rail cars bound for Treblinka. As with so many entries in the encyclopedia of Nazi atrocities, the depravity of that act and our inability to fathom such cruelty threaten to eclipse the individuality of the victims.

Historians push back against the obliteration of chaos, time and shame, but talented novelists have also offered their creative gifts in this sacred process of remembrance. And now, Jim Shepard, one of America’s finest writers, brings the Warsaw orphanage to life in “The Book of Aron.”

Drawing on his imagination and dozens of historical sources, the author has produced a remarkable novel destined to join the shelf of essential Holocaust literature. Although relentless in its portrayal of systematic evil, “The Book of Aron” is, nonetheless, a story of such startling candor about the complexity of heroism that it challenges each of us to greater courage.

The narrator is a poor Polish boy who introduces himself by announcing, “My mother and father named me Aron, but my father said they should have named me What Have You Done, and my uncle told everyone they should have called me What Were You Thinking.” With erratic beatings, constant disparagement and unending illnesses, this is hardly a nurturing environment, but Aron’s clear-eyed reporting and self-deprecating humor make him irresistible. “I was like something that had been raised in the wild,” he confesses. “It was terrible to have to be the person I was.”

The novel hangs on the delicate tension of that deadpan adolescent voice — never cute, never cloying. Aron’s wryness is always entirely unknowing. He relays his world to us just as he experiences it: He fails at school. His mom complains about everything. His little brother dies. How he feels about any of this is articulated only in the space between his sentences. “The next morning my father told me to get up,” he says, “because it was war and the Germans had invaded.” And with that news, his town slides into hell.

We read novels about the Holocaust with the burden of knowledge: the incalculable statistics, the sickening photos, the faint outlines of vanished shtetls. But Aron has only his own simple life by which to judge anything, so nothing surprises him. “Whether I was happy or unhappy,” he says, “I took things as I found them.” What he finds is an ever-escalating series of horrors, but he describes the Nazis’ humiliations and crimes with a child’s concentration on the specific. “That night two Germans showed up at our door looking for furniture,” he says. “They roamed around our apartment before deciding we had nothing they liked. They went next door to our neighbors with the radio and took two chairs and a soup tureen. The husband told us after they left that they’d pulled him around by the nose with pliers because he hadn’t said a courteous enough hello.”

From that captivating perspective, Shepard re-creates the shrinking Warsaw ghetto, running out of food and ravaged by typhus as the Nazis ship out everything of value. But for Aron, the war delivers freedom from the drudgery of school. He joins a small gang of kids who scour the ghetto for loot. “The destroyed buildings were a great playground,” he says, “and we always found something surprising in the rubble.” Aron’s innocent face is an asset as his parents tell him to stay close and be careful. “I told them I would and went on doing whatever I wanted whenever I wanted to,” he says. He’s a scamp, helping his buddies smuggle goods through a hole in the ghetto wall, but they know they’re playing against opponents who shove prisoners into open fires and shoot kids in the streets.

As terror escalates in this doomed city, the novel delineates Aron’s dangerously compromised position. While he and his friends smuggle anything of value into the ghetto, he falls under the influence of a corrupt Jewish police officer who demands information for his Gestapo bosses. The boy has no way to resist, no way to excuse the deaths that result and no capacity to understand what is happening to him. After witnessing a particularly shocking murder, he says, “On my way home my legs acted like I kept forgetting how to walk and I stopped in the center of the road. I threw my own cap away. A truck honked and someone finally dragged me to the curb.” Divorced from his own feelings, he is left only with his sensory reports. “I wiped my eyes so hard I blinded myself at first,” he says. “There was nothing for me to do and nowhere for me to go in the face of the pictures in my head.”

But where he goes next draws “The Book of Aron” into one of the most affecting acts of bravery you will ever encounter. In real life, the caretaker of the Warsaw orphans was a well-known writer, a progressive pediatrician named Janusz Korczak. When his orphanage was moved into the ghetto, he insisted on going with the children. And there, in those final weeks, Shepard imagines him taking a special interest in Aron. “You’ll be fine,” the good doctor tells him, brushing away the boy’s tears.

Let’s set aside puffery about the best novel of the month or even the year; Shepard has created something transcendent and timeless in this slim masterpiece — a portrait of an exhausted but determined man, locked in a futile battle he will not concede. “It’s Jewish honor I’m upholding,” Dr. Korczak says as he trudges around the impoverished ghetto with Aron, cajoling and demanding donations for his 200 charges. Back at the orphanage, he designs both chores and games, exhorting these sick and malnourished children to imagine they aren’t “living in the worst place in the world but instead were surrounded by grasshoppers and glowworms.”

But there’s a lot more here than pastel optimism. Shepard shows Korczak in all the private discouragement and desperate loneliness that could make him short-tempered with those who loved him. “I am unkind,” he admits late one night. “To work here you have to be unkind. You have to be smeared with crap, you have to stink, you have to be crafty.”

That logic leads Aron into an ethical dilemma that he’s too young and weakened to resolve, which fuels the novel’s suspenseful crisis. But there is no room for hope for the Warsaw orphans; that history is carved into the earth. Although Dr. Korczak was offered opportunities to escape, he refused to abandon his children and died with them in Treblinka. Still, Shepard dares to move his narrative down the asymptote of despair, and the moral heroism he describes on that path toward infinity, you will never forget.

Ron Charles is the editor of Book World. You can follow him on Twitter @RonCharles.

THE BOOK OF ARON

By Jim Shepard

Knopf. 260 pp. $23.95