When in the spring of 1942 the weather turned warm again, the Ostheer seemed to regain confidence despite the disastrous bloodletting before Moscow. Perhaps the combination of the renewal aspect combined with a feeling that they’d endured the worst was at the root of it. Whatever the cause, this buoyancy would be needed as the German army geared up for another offensive that would take them even deeper into this interminable land mass and the unknown dangers that lay in wait.

That summer Hitler tried once and for all to break the back of the Soviet Union by pushing not toward Moscow this time, but striking with only part of the weakened Ostheer into the rich oil fields of the Caucusus to the south near the Black Sea. Operation Blue, as it was called, started off with the same sweeping success as had Barbarossa the summer before, gobbling up swaths of territory deep into the Russian hinterland. A rejuvenated, reequipped and confident Ostheer, spearheaded by General Friedrich Paulus’ 6th Army and General Hermann Hoth’s 4th Panzer Army, formed a powerful column of armor and infantry and surged across the open plains toward the Don River and beyond, while waves of Heinkel, Junkers and Dornier bombers pounded the ground before them. Beyond the Don, the offensive converged upon an industrial city sprawled out along the west bank of the wide Volga River that had been re-named Stalingrad in honor of the Soviet dictator.

All along the horizon the combatants could marvel at pillars of oily black smoke rising from Stalingrad rising thousands of meters into the humid summer air: evidence of the merciless pounding the city was being subjected to at the hands of a Luftwaffe that showed no scruples where civilian casualties, eventually numbering in the hundreds of thousands, were concerned. As the 6th Army ringed Stalingrad’s remaining defenders and pinned their backs against the swollen river, Hitler thought that this time the victory would be decisive and final.

But Stalin refused to surrender his showpiece city. Nor would he allow any of its half million non-combatants to be evacuated, believing his soldiers would fight harder for a live city than a dead one. Such callousness only compounded the agony of its residents as a once-thriving metropolis was reduced to a burning pile of rubble while German formations methodically clawed their way through the obstructed streets—each of which was turned into a battlefield by the Bolshevik defenders. By late summer Paulus’ command controlled ninety percent of the city proper. But the ten percent still in Red Army hands provided a vital supply beachhead into which vessels of all shapes and sizes ferried reinforcements from across the eastern bank of the Volga and kept the defenders fighting. “Not one step back!” and “There is no land behind the Volga!” was Stalin’s official decree. It would be a fight to the death for Stalingrad.

Reporters pestered Paulus to allow them to officially announce Stalingrad’s capture to a glibly oblivious German public. But what only those suffering and bleeding and dying by the thousands on the front lines could know was that by autumn the momentum of the offensive had been broken and what was once a series of sweeping flanking maneuvers had degenerated into a street-by-street, house-by-house, cellar-by-cellar fight in which savagery on both sides would reach new lows unimagined by either people in peacetime. Still, it looked to those on the outside that any day Stalingrad would fall and Hitler would have his prize.

In an effort to finally put an end to resistance and secure the city, Paulus stripped both flanks of seasoned German units and left their defense out on the exposed steppe to less reliable Romanian and Italian allies. It still was not enough. The attack soon ground to a gruesome stalemate pinning the two armies against each other. They hunkered down in a surreal lunar landscape living a troglodytic existence amidst the ruins of a once beautiful urban center. Their positions were often so close they could overhear conversations in strange tongues echoing from the floors just above or below them. When forced to the surface, the soldiers scurried more like rats than men while dodging ubiquitous snipers. Long before the onset of the dreaded Russian winter, the trees were already twisted and bare as the constant shelling had shaken every leaf off every branch.

The Battle of Stalingrad had become a nightmare and the city became a mass graveyard for hundreds of thousands. The Landsers there began to use the term “Rattenkrieg,” the war of rats, to describe their hellish existence. One German officer wrote in his diary: “Stalingrad is no longer a town. By day it is an enormous cloud of burning, blinding smoke; it is a vast furnace lit by the reflection of the flames. And when night arrives, one of those scorching, howling, bleeding nights, the dogs plunge into the Volga and swim desperately to gain the other bank. The nights of Stalingrad are a terror for them. Animals flee this hell; the hardest stones cannot bear it for long; only men endure.”

Hitler’s grand plan to seize the Caucuses oil fields, which his men never reached, and simultaneously erase one of Russia’s most important industrial centers west of the Urals had been spoiled by the tenacity of the Red Army and fanatical devotion to their Motherland for which they were prepared to die and take as many Germans with them along the way. It was clear that Russia was far from broken, and probably never could be broken. In mid-October the 6th Army spirits sank as Paulus’ men watched with grim trepidation as the first snowflakes fluttered down onto the faded green of their lice-infested uniforms. The Ostheer was even deeper into enemy country than the year before, weakened and immobile, facing another brutal winter on the steppe.

Meanwhile, as Hitler denied Paulus’ requests to abandon Stalingrad before his men were all dead, with its veteran forces concentrated in and around the city and along the river, the 6th Army now found itself dangerously exposed as Soviet Generals Zhukov and Vasilevskiy–and “General Winter”–feverishly crafted their own plans for wiping out the invaders in their midst.