by Sam Kean
After checking over their gear on Saturday afternoon, nine of the ten Norwegian soldiers (the tenth stayed behind to guard the hut) set off for Vemork at 8 p.m. They were discovered almost immediately. Four youths from a local village—two men, two women—had snuck off to some nearby cabins to do you-know-what, and they bumbled into the Gunnerside crew. Embarrassingly, two of the commandos knew one of the men. He was no spy, but they seized him by the collar and threatened him with all sorts of hellfire if he breathed a word about their presence. They then herded the lovers into a single hut and told them not to leave until noon the next day. The wide-eyed youths obeyed.
The soldiers skied most of the twenty miles in, wearing white camouflage suits and rucksacks. Along the way they dropped below the tree line and began tramping through a patchy forest. They could hear the waterfall that powered Vemork now, and as they came into a clearing they suddenly spotted—off in the distance, in the moonlight—the building that had dominated their thoughts for months. It must have been a majestic sight. As one historian said, “If a medieval king had searched all of Norway for an impregnable place to build a castle, he could not have found anything better than the shelf of rock on which the Norsk Hydro plant stands.” In peacetime, the eight-story granite building would have been glowing like a glitzy hotel, every window ablaze. During the war, with the windows blacked out at night, it looked like a giant sarcophagus. The Gunnerside crew could nevertheless hear, even above the waterfall, the hum of machinery. Vemork had produced ten pounds of reactor Juice that very day.
Ducking back into the forest, the commandos found a switchback road winding down toward the gorge. It was tedious going, so they eventually decided to cut straight down the gradient instead. This was basically a controlled plummet through the snowy undergrowth: their backs were flat against the ground and their skis were splayed in front of them as brakes. Every few feet they loosed a mini-avalanche.
Halfway down, some of the party reached a stretch of road and stopped a moment to let their companions catch up. Seconds later, their world got much brighter. They swiveled, and saw two pairs of headlights on the road—two buses bringing workers in. They leapt for cover behind a snowbank, but could only watch in horror as their companions continued skidding down the slope.
The men on the slope had seen the headlights, too, and began grabbing at tree roots and rocks, flailing for anything to slow their awful momentum. A few did manage to stop, but two of them continued tumbling and almost crash-landed onto the roof of one bus.
Somehow, though, none of the bus passengers noticed. It was late and dark and everyone was exhausted. They continued to stare dully forward, their minds so consumed with work or war that even the sight of something amazing—two soldiers falling out of the sky—couldn’t penetrate their gloom. The bus rumbled on and disappeared around a bend. After taking a moment to catch their breath and shake their heads, the Gunnerside nine continued descending.
At the bottom of the slope they buried their skis in an impromptu igloo for the return trip—if there was one. Then they removed the guns and grenades from their rucksacks and stripped off their white snowsuits to reveal khaki British uniforms beneath. They’d decided to dress as British soldiers to minimize the chance of reprisals against the plant workers and local villagers. This cover would crumble if the Germans captured and interrogated them, of course, but that seemed unlikely. For one thing, most of the Gunnerside crew didn’t expect to live through the assault: just before leaving Great Britain they’d all written goodbye letters to their loved ones. And in case of capture, each man took from his rucksack, in addition to the guns and grenades, a rubber capsule filled with cyanide.
They reached the lip of the gorge at 10 p.m. As expected, two sentries were patrolling the suspension bridge, with fifteen more guards in a hut just beyond that. A machine gun glowered from the rooftop, and they knew from intelligence reports that three more patrols were likely wandering the grounds. But as Rønneberg suspected, no one was guarding the gorge itself. Grinning at their luck, they started down.
At the bottom of the gorge they found a swift stream and scouted around for an ice bridge, testing various spots with their toes. The only suitable one felt as slick as oil and was submerged in rushing water. However precarious, it held their weight, and all nine saboteurs inched across.
Now for the real challenge, the six-hundred-foot ascent. Water was trickling down the sides of the gorge, making the rock face slick, and their fingers had already gone numb in the cold. If not for the gnarled junipers, the climb would have been impossible. The bushes also saved one commando’s life. He was pulling himself up to a small ledge when his grip faltered. He kicked and scrambled and managed not to fall—but found himself dangling by one hand two hundred feet off the ground. Calming himself as best he could, he began patting the cliff face around him with his free hand, feeling for a new grip. Nothing—just bare, wet rock. With no other choice, he began swinging side to side, groping a little farther each time. His fingertips finally brushed the edge of a bush; but he couldn’t reach it while still holding on with his other hand. The wind began to kick up now, threatening to pry him loose from the rock, and he realized he had to act soon.
Fighting every instinct in his body, he began swinging again, really kicking his legs out. After one final lurch, he let go. For a moment he was suspended in air, holding nothing. Then he snagged the bush like a Nordic Tarzan. It gave some, bending like a branch—but finally held. After a few deep breaths he resumed climbing. Four hundred feet to go.
At 11 p.m. all nine men heaved themselves over the lip of the gorge, then crept forward and ducked behind a transformer to rest. The guard was changing soon, so they took a moment to eat some chocolate and crackers and relieve themselves. As all young soldiers do, they also cracked jokes and talked of women. There was no need to go over the mission again. Everyone knew his role: five men would provide cover, with a demolition team of four penetrating the plant.
After the guard change, they waited another half hour for the new sentries to get good and bored before moving forward. Wherever possible, they followed routes through the snow that Nazi patrols had already trod, stepping in their footprints to conceal their tracks. At the end of a railroad spur on the perimeter of the plant, they found an unguarded gate and cut the lock. At this point five men peeled off and trained their tommy guns on the barracks and guard tower to provide cover. The demolition team, including Rønneberg, snipped a hole in a fence and made for the heavy-water plant. The team then further fissioned into two pairs of two and split up to try different entrances.
Spies inside the plant had assured the British that the Nazis were lax about security, but the commandos found every last door bolted shut. The windows were all locked, too. Frustratingly, through a chip in the blackout paint over one window, Rønneberg could see the heavy-water cells in the basement: they looked like oversized fire extinguishers, shiny gray cylinders four feet tall. His heart pounding, he was powerfully tempted to smash the window and take his chances—they were so close! He restrained himself and tramped on.
As a last resort Rønneberg and his partner tried a utility duct. They reached it via a short ladder, and after clawing aside the snow packed into the entrance, they began belly-crawling forward, wriggling like worms amid the cables and wires. Unfortunately, the trailing commando’s pistol came loose during this effort. It dropped, and clanged on the metal beneath them when it fell. They froze, bracing for an alarm. But the throb of machines masked the noise, and after a moment of rest, they slithered on.
Having memorized the plant’s layout, they snaked around to a point near the heavy water room and dropped fifteen feet to the floor through a hatch, landing in a parachute roll. After months of preparation, they were now facing the final door. A sign there read, in German and Norwegian, NO ADMITTANCE EXCEPT ON BUSINESS. They pulled their guns, nodded, and burst in on the guard.
By all rights the Germans should have posted a top soldier here—an alpha ki
ller, their Ajax or Achilles. After all, the entire Nazi nuclear bomb project depended on this room. As it was, they’d posted a frumpy Norwegian pensioner inside, who took a good three seconds to turn around and just about messed himself when he did, finding a pistol buried in his solar plexus. Realizing he was no threat, the commandos disarmed him, pushed him into a corner, and told him to shut up.
Simple enough instructions, yet the guard proved incapable of following them. As the saboteurs unpacked the almond-scented Nobel 808 and started kneading it into half-pound sausages, this pompous old goat—name of Gustav—had the audacity to begin bossing them around. There were eighteen fuel cells in the room, nine on each side, and the commandos planned to wrap a sausage around the base of each and daisy-chain them together with detonator cords. But every time they got near one, Gustav had a fit. Those are electrolysis cells, he called out. Very expensive. Be careful about shocks. Oh, and mind the lye in the corner there! You’re liable to burn yourself. It was a scene of Shakespearean low comedy: the know-it-all dogsbody prattling on and on, oblivious to the danger he’s in. The gravity of the situation finally struck Gustav when, after several seconds of squinting, he realized that the commandos were handling fuses and detonators. Good god, he squealed, be careful. You’re liable to blow up all this equipment.
“That’s pretty much our intention,” deadpanned Rønneberg’s partner.
That shut Gustav up. And now that the commandos could get a few words in, they enacted a little farce of their own. Still worried about reprisals, they wanted Gustav to believe they were British. So they began reciting a few lines they’d memorized, making heavy-handed references to merrie olde England. Incongruously, they held this dialogue in Norwegian, but Gustav looked impressed.
All the while, the duo continued to wire up the explosives. They’d just about reached the halfway point when they heard a crash behind them—and wheeled to see a shattered windowpane. Someone had punched through from outside.
The Gunnerside duo froze, braced for guards, grenades, the tip of a gun. Had Gustav secretly signaled someone? Had the old poacher betrayed them at last? Neither, it turned out. A second after the pane shattered, a familiar gloved hand reached through. The other two commandos, tired of plodding about in the snow, had said to hell with stealth and smashed the basement window.
It was a bold move—bold and idiotic. Rønneberg had to stop working to help the two inside, and as he knocked aside the shards in the frame, he sliced his right hand open. This rendered him useless for laying explosives, which was a problem considering that he was the explosives expert. All he could do now was twist fuses together with his other hand. Smashing the blacked-out window also allowed light to pour into the yard—a veritable beacon to any patrols. So another commando had to stand outside and block the hole with his arse, which rendered him useless as well.
And if all this chaos weren’t enough, the commandos soon heard an ahem from offstage. Gustav again.
What now? Rønneberg growled.
My glasses, he said. I’ve misplaced them somewhere in the room. I must have them.
You can’t be serious.
Well, I can’t see without them.
Tough.
Please help me look. With the war on, I won’t be able to get another pair if they’re destroyed. I’ll lose my job.
Rønneberg couldn’t believe it. Here he was, an elite commando leading the most dangerous mission of his career, with the fate of the Nazi atomic bomb in the balance—and now he had to drop everything and search for an old man’s spectacles.
“Where the hell did you put them?” he snapped. Gustav motioned toward the desk. Rønneberg found his glasses case there, tossed it to Gustav in the corner, and returned to the fuses.
Only to hear, a moment later, another ahem. Rønneberg turned, incredulous, to find Gustav staring down into the empty shell of the case. “The glasses aren’t in there.”
“Where the hell are they, then?”
“They were there when you came in,” Gustav whimpered, as if this was all Rønneberg’s fault. Laying his work aside again, the commando began ransacking the desk, all but flinging things aside. He finally found the glasses folded between the pages of a ledger and handed them over. Now shut up.
Thankfully, the other commandos had nearly finished wiring the explosives by this point and could turn their attention to escaping. Having relieved Gustav of his keys, they left the heavy-water room for the hallway outside and unlocked a door that led into the yard; they also dragged Gustav into the hallway so he could run for safety once they were gone. About all that remained to do was light the fuse.
That’s when they heard footsteps.
Everyone froze. They listened harder, and sure enough, they heard the click of shoes on a staircase adjacent to the hallway. The commandos swore and took cover, pistols drawn. A moment later another guard appeared, one far younger than Gustav. Luckily, he proved no more quick-witted, and he yelped in surprise as the commandos surrounded him. A few questions revealed him as a fellow Norwegian, someone with no desire to risk his life alerting the Nazis. So the commandos shoved him next to Gustav and returned their attention to the explosives.
At last, at 1:13 a.m., everything was ready. Rønneberg reached into his pocket, removed a few patches from a British parachute squadron, and tossed them on the ground—one last diversionary tactic to prevent reprisals. He then struck a match and lit the main fuse. It would burn for thirty seconds. Cutting things mighty close, Rønneberg then released Gustav and the young guard to run upstairs and lie down. Keep your mouths open until you hear the blast, he advised. Otherwise, the sudden pressure change will explode your eardrums. Only after the guards had scampered off did the commandos themselves turn and sprint.
From the outside, the noise of the explosion was disappointingly meek—“all bass and no treble,” as one historian remarked. This left some of the Gunnerside team fretting, convinced that the explosives had failed. They needn’t have worried. The thick walls of Vemork had simply muffled the pyrotechnics; inside the basement, the Nobel 808 had done its job beautifully, splintering the fuel cells and spraying heavy water everywhere. Shrapnel from the cells also pierced the pipes along the ceiling, flooding the room with regular water and washing the equivalent of 770 pounds of pure Juice down the drain.
Even the Nazis who showed up later to assess the damage had to admire the precision of the work. They’d initially taken a hundred hostages from the local population to exact revenge, but upon realizing that no mere amateurs could have pulled this off, all hundred were freed. The official German report on the incident stated that there was “not extensive damage, except at the place where the attempt was made, and there the devastation was total.”
The nine commandos left the way they came. They hadn’t fired a single shot, and they politely shut the open railroad gate behind them. Then they careened down the gorge, recrossed the ice bridge, and scrambled up the other side, hoping to make a quick escape. Unfortunately Rønneberg’s hand, still bleeding, marked an easy trail of crimson for the Nazis to follow in the snow. Worse, Vemork’s sirens began screaming not long after they ascended the gorge. The commandos looked back to see several search parties setting out, their flashlight beams swinging like scythes in the dark. After grabbing their skis from the igloo, the crew took off along a nearby road, ducking out of sight whenever a vehicle full of guards roared past.
This being Hardanger, snow began to fall as soon as they reached the top of another switchback road. But for once they welcomed a good old-fashioned blizzard. The snow covered their tracks, covered even the blood, and while it made for hard going, it bogged down the search parties far more than it did these veteran skiers. A few hours later they reached their cabin unmolested. They managed to stay awake just long enough to drink a toast of whiskey. Afterward they collapsed for eighteen hours of sleep, then rose the next day and scattered to the ever-present wind.
CHAPTER 27
Consolations of Philosophy
Werner Heisenberg had a frustrating winter in 1942–43. He was still building reactors, still doing fission research, but somehow the pathetic, striving Kurt Diebner had vaulted past him. Heisenberg had always favored a certain geometry for his reactors, with alternating layers of heavy water and uranium; sometimes the layers were circular shells, more often sandwichlike slabs. In either case, the arrangement wasn’t ideal. After a uranium atom fissions, the neutrons that emerge can fly off in any direction, but not all directions were equally good. Imagine a neutron flying straight up or down from the surface of a flat slab. It would quickly encounter heavy water and slow down, thereby helping the chain reaction along. But if the neutron flew out sideways, it would stay within the uranium layer and encounter only other uranium atoms—meaning it would never slow down. These sideways neutrons were wasted.
Diebner sidestepped this problem with an innovative “lattice” design: instead of slabs or shells, he broke up the uranium into tiny cubes and suspended them in a tank of heavy water. This expanded the geometry, since the flying neutrons could now find material to slow them down in all three dimensions. (Enrico Fermi’s reactor pile in Chicago, with small plugs of uranium embedded in graphite, used the same idea.) Setting up Diebner’s experiments took weeks of drudgery, and he had to coat every last uranium cube in lacquer to prevent it from mixing with heavy water and catching fire, but the huge spike in neutron production—110 percent, compared with Heisenberg’s 13 percent—proved the superiority of his design. And the really vexing thing was that Diebner did all this with Heisenberg’s table scraps. Heisenberg always got first dibs on heavy water and uranium, while Diebner made do with leftovers. The military hack nevertheless beat the pants off the Nobel laureate.