What she remembers is the acrid smell of burning sugar. The way it singed the lining of her nose.

When Marina emerges from the stairwell onto the roof, she can already hear the low rumble of the approaching Junkers. Schlisselburg fell on Monday, and so Leningrad is completely surrounded now, cut off from the outside world. Two nights ago, the Germans began dropping incendiary bombs, setting fires around the city. Wardens, armed with shovels and buckets of sand, have been posted in the various halls and around the perimeter of the roofs of the museum. Marina is a fire spotter, one of a pair posted to each observation platform on the roofs of the Hermitage.

She climbs the dozen steps up onto a small wooden platform. Olga Markhaeva, a curator of Netherlandish painting, is already up here. Her husband, Pavel Ivanovich, is in the same Volunteer division as Dmitri. Olga greets Marina and then hands her a pair of binoculars, which Marina hangs around her neck.

“Look,” Olga commands, pointing to the south.

Through the binoculars, Marina follows the droning sound and finds a slowly approaching shadow against the clouds. All summer, there have been planes, tiny specks like mosquitoes circling and diving over the city. But this is different. She cannot make out individual planes, only a menacing phalanx of darkness.

It is not quite dark, and, standing up here on this platform, Marina feels exposed to the sky like a mouse. There is no place on the vast expanse of the roof to hide. Cold with dread, she eyes the door leading back down to the hall below. Were it not for Olga Markhaeva’s presence, she doubts she would be able to resist retreating back down into the safety of the museum.

The Hermitage can’t possibly be a military target, but that is no comfort. There is no sense to any of this, nothing a sane person can understand. Though in the abstract, everyone knew that the Germans were close, when the first shells came screaming into the city a few days ago, it was like a fantasy, surreal and outrageous. Stunned, people looked to each other, disbelieving. This could not be. Not here, not in Leningrad. It is lunacy. They fire long-range missiles into the city, killing women and children and old people at random. For what? And why try to burn down a city? What good is victory if there is nothing left to claim?

Marina thinks of Dmitri and his love of rational argument. What would he do with this? Perhaps there is a logic to this that can be seen only from a cool distance: the two and a half million inhabitants of Leningrad a pin on a map from somewhere in Berlin. But here she is too close to see any pattern. Looking at the horrific swarm bearing down on them, it is easier to believe the explanation on the radio: that the enemy is uniquely evil.

“There must be fifty of them tonight,” Olga says. Her voice is calm, with no hint of the terror Marina feels.

The drone of the Junkers is louder. They are clearly visible now, a dozen, two dozen, maybe more. They move methodically in formation. The ack-ack guns sputter wildly, and she hears the thudding of explosives to the south. Through the binoculars, she picks out a burst of flame near the edge of the city, out by the Vitebsk railroad depot, then several more clustered together. Then the fires are sprouting in a straight line across the dark landscape of the city, springing up like rows of orange tulips. The thunder of engines envelops her, and suddenly bombs are bursting in the Neva, fountains of spray blooming up the length of the river. The platform shudders in the wake of each explosion. A searchlight sweeping the sky catches one plane after another in its path, and Marina sees the swastika on a wing directly above her.

It is not fear, exactly-that is not why she stands so rooted and still, her breath locked in her chest. She is mesmerized by the awful beauty she is witnessing. As soon as the planes are past, though, Marina realizes that her legs are trembling, so much so that she has to grip the rail of the platform with both hands in order to remain upright.

The two-way radio inside Olga’s jacket is crackling. She reaches inside her jacket and pulls it out.

“Has anything hit us?” It is Sergei Pavlovich, down in the warden’s office.

Olga shouts into the radio. “Just a moment. Over. Marina Anatolyevna?”

Marina looks at her and then realizes the binoculars are strung around her own neck. She releases one hand from the railing, and brings the glasses up to her eyes, but her hand is shaking too hard to steady the image. It jumps and wavers.

Olga watches her calmly and waits.

Marina releases her other hand and stiffens her grip on the glasses. She scans the roofs of the Hermitage buildings and across to the gabled roofs of the Winter Palace, where another platform is rigged. And then she checks again, slowly, methodically. Amazingly, the Germans seem to have missed the museum entirely. She directs her binoculars toward two still figures, their counterparts on the far platform. Other figures stand at their posts. No one is moving. She can’t see any fires.

“Nothing. I don’t see anything,” she tells Olga, who relays the information to Sergei.

“Check the perimeter,” Olga reminds her.

Marina sweeps her glasses up and down the embankment. Just across the river, in the gardens next to the Peter and Paul Fortress, the roller coaster has caught fire. The huge wooden structure is ablaze, a writhing dragon of orange flame. She turns and scans the buildings along Millionnaya Street and ringing Palace Square, inscribing a slow circle. Then she looks for spots of fire farther out in the range they are assigned to report on.

“There’s a fire near the Trotsky Bridge, past the Trotsky, I think.” Without lights, it is hard to find landmarks, but she calls out approximate locations to Olga, who relays them to Sergei.

“And another one-this one looks bad-near the Engineer’s Castle.”

There are nearly a dozen fires within a kilometer’s radius of the museum. She relays them one by one to Olga, trying to be accurate.

“On the far side of the Moyka, near the Stroganov Palace, I think. No, wait…” As she is watching, she spots a fire truck already rattling down Nevsky toward the fire. But it races right past the fire and turns south onto Vladimirsky. Other trucks are moving down the avenues, their bells ringing, passing fires that burn unchecked. They are all heading south. When Marina turns her binoculars in that direction, she finds an enormous column of smoke. The plume rises high into the sky above the city. At its base, it is tinged with red.

“My god.”

“What is it?” Olga is standing at her shoulder.

“I don’t know. It’s near the Vitebsk station.” She unstraps the binoculars and hands them to Olga.

Later, she will find out that what they are witnessing is the burning of the Badayev warehouses, where the food supplies for the entire city are stored. Or maybe they know this already; maybe Sergei has reported back to them the rumors already circling the city. Tomorrow, the worst of those rumors will be confirmed. Three thousand tons of flour, thousands of kilograms of meat, a molten river of sugar flowing into the basements of the charred warehouses. She cannot know this now, but lodged in Marina ’s mind, as real as anything else, is the chilling certainty that they are witnessing catastrophe.

Down in the streets, there is a rushing of dark figures, the sounds of yelling, the rattle of antiaircraft fire though there are no more planes. But from up here, it seems silent, the terrible silence that might accompany the end of the world. After they have reported the fires within their range of visibility, they stand for a long stretch of time. They watch as sections of the roller coaster buckle and crash to the ground. Searchlights sweep the sky, swords of white light crossing, swishing apart, and crossing again. A full moon rises like a blood orange on the horizon. They may not leave their post, and no one comes to relieve them. Marina wants to sit down, but Olga remains standing, erect as a soldier. Up and down the long series of roofs, wardens stand watching the distant conflagration and the smaller fires dotting the city. Their silhouettes blend into the rows of green copper statues that line the perimeter of the Winter Palace roof, warriors and gods that have vigilantly guarded the palace for nearly two centuries.