The Hess Cross

by James Thayer

  "As you can see, this was once a squash court. The courts haven't been used for years, so most students have no idea they exist. Keeping it secret here is much easier than if we had built a new building to hide it in." Fermi grasped the rail, leaned over it slightly, and said, "That's the pile."

  Hanging from the ceiling of the squash court in front of them was an immense square balloon whose thick hide concealed its contents. The balloon hung to the floor of the court ten feet below them, and in its side facing the observation platform was an aperture through which workmen were steadily passing. Each carefully sealed the flap behind him as he entered or left the balloon.

  "The graphite gives off a fine dust that clogs the gauges and would probably interfere with the reaction. So we've sealed the dust inside the balloon, and just before the experiment, we'll pump it out and open up the balloon."

  Fermi walked to the sheet-covered table and asked the youthful electrician if progress was being made. The electrician, whose curly black hair dominated his face, was myopically squinting at a structure which to Crown looked like a vastly complicated fuse box. He was digging around in it with a pair of rubber-handled tweezers and was so absorbed in his work that Fermi's question startled him.

  "Oh, fine, Professor, fine. I'm just doing a routine check, probably for the tenth time. There's no problem. It may not look like it, but I can put all this together again."

  "Excellent. Let's take a look at the balloon, John."

  They descended an almost vertical circular stairway to court level and entered the squash court through the miniature door peculiar to indoor courts. Fermi held open the balloon flap, and Crown and Heather crouched through the canvas wall. Heather immediately felt dirty. The air was thick with graphite dust that clung to her as if she had a magnetic attraction for the particles. Her eyelids scraped as she blinked, and her tongue felt coated. She brushed her cheek with the back of her hand, and her skin was slimy.

  Enrico Fermi didn't seem to notice the graphite dust. "This pile is just what the name implies—thousands of graphite blocks placed in a square pile twenty-four feet in diameter. It's very simple in appearance, as you can see, just a huge black square. But it consists of lumps of uranium spaced eight and a half inches apart, separated by the graphite blocks. Right now, there are about thirty-five thousand of the blocks on the pile, and we will eventually have forty thousand or so. Each layer of solid graphite blocks alternates with a layer of blocks that have holes drilled through them so uranium can be placed in the holes. Now, you may be wondering why we need all these graphite blocks."

  Not particularly, thought Crown.

  "The reason is that a chain reaction cannot occur in pure uranium, because when the neutrons and nucleus interact, too many of the little devils escape," said Fermi, beaming at the ingenuity he was about to reveal.

  "What little devils?" asked Heather.

  "Neutrons. You see, the neutrons travel so fast that far too many of them escape to allow a continuing reaction. So we use the graphite to slow them down. Because the graphite does not absorb many of the neutrons, most of the neutrons it slows down bounce back into the uranium lumps. We thus can keep the reaction going, a chain reaction.

  "The magic word here is 'controlled.' What must be prevented is a spontaneous reaction, where the chain reaction gets out of conttrol. The Lord only knows what would happen if it did. So we have a control rod made of cadmium, which is inserted into the pile to prevent the reaction from beginning. The rod absorbs extra neutrons. It is our brake. When we want the reaction to start, we'll slowly pull the rod out of the pile, thereby allowing the buildup of neutrons and nuclei reacting with each other."

  The cadmium control rod protruded from a pile a foot above Crown's head. For a mechanism with the importance of the rod, it had a decidedly innocuous appearance.

  A workman lugging a graphite block entered through the flap. Fermi held the porthole open and gestured Crown and Heather through it. Heather swatted her skirt and blouse, to no effect. It would take several showers before the dry, greasy feeling of the graphite was removed from her skin. She hoped the clothes could be salvaged.

  "If our experiment doesn't work, there'll be no cheap energy. None of the things I mentioned in my office will come to pass," Fermi said as they passed the checkpoints on the way out of the court area.

  "What about the bomb?" Crown asked, walking slightly behind the physicist as they approached the last sentry station.

  "There will be no bomb if my experiment ten days from now fails."

  "My chief was vague about the potential of such a weapon. Have you calculated what this bomb could do?"

  Fermi waited until they were beyond hearing range of the sentries, then said, "Yes. We figure that one bomb small enough to be carried in a conventional bomber would have the rough equivalent of twenty-thousand tons of TNT. That's enough to vaporize most of a large city. And the explosive force is not the only dangerous effect of an atom bomb. The reaction irradiates the dust particles the explosion kicks up. Anyone coming in contact with these windblown particles would die or get very sick from the radiation." Fermi's voice hollowed and seemed to drift as he spoke of the destructive capabilities of his research. It was clear he preferred to dwell on peaceful energy uses of the atom, but heightened interest compelled Crown to ask, "Has anyone considered how such a weapon will change warfare?"

  "Oh, yes. A few military theorists are propounding the question to themselves. What they come up with is obvious."

  "Perhaps not that obvious to some of us." Heather grinned playfully at Crown. He made a show of ignoring her.

  "They believe, and rightly so, that within a decade or two after the first bomb is produced, twenty or thirty countries will have it. You see, the requirements for producing such a weapon are widely held. Many countries could produce the bomb in a decade if they had that priority. Our research, as novel as it is, will be impossible to keep secret for long. History suggests that most of what we learn and produce will be for sale on the common market within a few years."

  They passed the iron door and stepped through the vestibule to the sidewalk in front of the grandstand entrance. The November clouds were breaking, and it was brighter than when they had begun the tour. Crown didn't know if he was squinting because of the sun or the graphite particles.

  Fermi shaded his eyes with a hand and scanned Ellis Avenue. "I try to spot the guards once in a while," he said. "It's not that hard. They don't look as anemic as the students. There's one."

  The physicist pointed to a tall man wearing a wool sweater and standing near a newspaper vendor's booth forty yards away. He carried a rolled newspaper under one arm and did not try to hide his stare. Fermi on the street made him and his partners nervous. A laundry truck stopped in front of the lab across the street, and a squat, powerful man wearing overalls climbed down from the cab, slowly walked to the rear of the truck, and tinkered with the door latch.

  "The laundryman is another," Fermi said. "I only need to stand here for a few minutes before the laundry truck, a Tribune newspaper truck, and about a dozen men trying to be casual surround me. It's amazing. I hope they know who you are."

  "They do. You were talking about how the atom bomb will change warfare," Crown said.

  "Well, as I said, many nations will ultimately get the A-bomb. What's worse yet is that there will be no effective defense against it. If a country sends ten bombers against a city, surely one or two will make it past the enemy's defenses. And one is all that's needed.

  "The natural result of this is that mutual suspicion among nations is bound to increase. Not only will the U.S. have to worry about the heavily industrialized and populated countries, but also about any country that can afford the weapon. The bomb won't be prohibitively expensive. World politics will change, believe me, when the U.S. must concern itself with every South American despot who purchases a bomb and a delivery system."

  Crown felt twelve pairs of hard eyes on the three of them. The guards were slo
wly closing in, wondering why the scientist was on the street, and feeling very uncomfortable that no reinforced-concrete walls surrounded their charge.

  "Come on, Professor. Heather and I'll see you to your lab door. We're making these boys antsy. One last thing," Crown said. "You keep using words like 'theoretical' and 'potential.' Aren't you sure you'll have a self-sustained nuclear reaction when that pile gets high enough?"

  "Well, according to my slide rule and blackboard, this will work. If I'm right, when the pile is completed ten days from now, we will enter a new age, the atomic age. And I can't foresee anything that could go wrong."

  VII

  OWLS HEAD, MAINE. Perhaps it is the most harshly beautiful peninsula in the United States. Jutting out two and a half miles into West Penobscot Bay, Owls Head protects the village of Rockland from the Atlantic Ocean's fierce pounding.

  The November wind is relentless, tossing and confusing the shore. Tons of white water drown shore boulders and drop away, to regroup, leaving rivulets coursing down the rocks, splashing pocket to pocket, irresistibly, to the sea, only to be launched at the boulders again. Wind froths the wave crests and hurls spray at the land. Wet gusts swarm over the rocks and moan inland. Crippled and humbled by the wind, only a scattering of gnarled beach shrubs and salt grass survives the Owls Head winters.

  The brunt of the winter storm hits Owls Head point, a quarter-mile outcropping on the tip of the peninsula. Here the wind rages against the stumpy lighthouse, as if in retaliation for its effrontery in breaching the point. The beacon sits on a wooded promontory fifty feet above sea level, but it is not immune from the icy seawater spray. The lighthouse normally guided ships entering Rockland harbor, but war had doused its light, and mariners relied on blue-can buoys. On this winter night, the mute buoy rose and fell implacably as giant swells raced underneath.

  Owls Head's chilling winters and cool summers had beaten back the land speculators and summer home owners that infested the Atlantic coastline to the south. With the exception of the tiny fishing village of Owls Head, the oceanside of the peninsula was uninhabited. Darkness and the November storm ensured the absence of beachcombers on the point. Owls Head that night was perfect.

  German submarine U-513's attack periscope broke the ocean's surface two miles east of Owls Head. For several seconds the periscope alternately submerged and surfaced as the swells passed over it. Then it gained enough height to clear the wave crests, and the periscope head swiveled in a complete circle. The shaft moved very slowly through the water to avoid stirring the phosphorescent sea.

  "Bridge watch. Stand by."

  "Aye, Herr Kaleun."

  The watch hurried into their oilskin slickers and sou'westers and helped each other into the tight rubber pants. Heavy binoculars hung around their necks. They pushed their hands into waterproof gloves. Normally the three lookouts would dread the approaching watch, a four-hour stint on the bridge, exposed to the freezing rain and spray. After a few minutes, the arms numbed from holding the binoculars to the eyes. Failing to scan the horizon every fifteen seconds was a court-martial offense. But if all went well this night, they would be on the bridge less than five minutes.

  The air in the control room was stifling. U-513 had been running submerged for more than forty-five minutes. Despite the air, none of the crew complained about the submerged run. It was a welcome respite from the pitching, rocking surface journey during the three days of storm. The sub had been at sea for more than two weeks, and this was the worst weather it had encountered.

  "Horizon's clear, Herr Kaleun," said the chief engineer, using the naval abbreviation for the commander's rank, Herr Kapitänleutnant. "Land directly east at ninety-five hundred meters."

  "Bottom?"

  "Eighty-five fathoms, sir."

  "Sub depth?"

  "Two fathoms."

  "Prepare to surface."

  A warning bell rang through the sub. Acting reflexively after scores of drills, the stokers jumped to their diesel engines, but then remembered they would not be firing them during this surfacing.

  "Surface. Blow the tanks, Chief."

  A low sibilation increased to a sharp hissing as compressed air rushed into the sub.

  "Horizon report."

  "The same, Herr Kaleun," reported the first watch officer, who had replaced the chief at the scope. "Land to east, ninety-five hundred meters. Nothing more."

  "Open the bridge hatch."

  Fresh, cold air was palpable as it poured through the hatch and conning tower down into the control room. The three lookouts scrambled up the conning-tower ladder and continued up onto the bridge. They immediately posted themselves on the bridge and began searching for planes, ships, anything. Five seconds later they were drenched as saltwater foam splashed over the bridge. None of them lowered their binoculars.

  "Permission to enter, von Stihl."

  Erich von Stihl grasped the control-room hatch panels to avoid tumbling as the boat lurched to port, dropped several feet, and rose again. He had long been over the sea sickness that had plagued him during the first few days of the journey from Germany. Despite the months of training for this mission, often on a raft on stormy seas, the first day out of Trondheim he had vomited like a rooky sailor. Some of the veteran sub crewmen had also been sick, but von Stihl suspected it was the effects of their alcoholic three-week leaves prior to sailing. He stepped inside the control room and approached the commander, who was stooped looking at a gauge on the wall.

  "From the pain in my ears, I guess we just surfaced, Herr Kaleun."

  "That's right, Colonel. Any problems with your wet suit?"

  "No, and no problems for my men, either. We're ready to disembark."

  "I don't envy your journey. The sea is force five, and in a small raft, that's dangerous."

  The commander did not look up from his panel of gauges. He wore nothing on his sweater or cap to distinguish him from the other fifty sailors on the sub. He had last shaved and bathed two weeks ago and looked and smelled as molted as his crew.

  Whenever the ship was on the surface, the commander's face was screwed with tension, almost as if he was in pain. The U-boat was the most effective weapon in Germany's naval arsenal. The only warning to an enemy convoy it usually gave of its presence was when a tanker erupted. Then the sub disappeared, tailed the convoy, and struck again. The U-boat was a silent, assured killer.

  But whenever the sub was on the surface, it was in danger from shore batteries, subchasers, and destroyers, and, most deadly, airplanes. The antiaircraft guns aft of the bridge were impotent and were used only as a last recourse. The sub's protection was its ability to dive quickly. And this depended on the spotters who stood their chilling vigil whenever the sub was on the surface. At the cry "Airplane," the lookouts would jump below deck, the hatch would be slammed shut, the ballast tanks flooded, and the sub would dive. The crew trained endlessly, until they could be submerged forty-five seconds after the first warning. Most emergency dives were caused by seagulls mistakenly identified as enemy fighters. No spotter was ever reprimanded for a false call. Rather a hundred unneeded emergency dives than one too late. Enemy planes seldom missed a sub on the surface.

  Sixty seconds had passed since U-513 surfaced. The commander called above, "Report from the bridge."

  "Land nine thousand meters east, nothing else, Herr Kaleun," cried one of the spotters.

  "Compressor, Chief?"

  "Compressor checks, sir."

  "You're on your way, then, von Stihl. Good luck, whatever it is you're doing."

  "Thank you, Herr Kaleun."

  Von Stihl climbed out the hatch to the bridge. His two men who had been waiting in the petty officers' quarters followed him out.

  Good riddance, thought the commander. Delivering the three men to this point two miles off the Maine coast had been his sole mission this time out. He had been forbidden to intercept American convoys en route, and unless he was lucky on the return trip, he would have no victory pennants to fly from
the periscope when they returned to Trondheim.

  Seldom were passengers allowed aboard a U-boat. When they were—typically pesty journalists—they worked as lookouts. But these three men had been deadweight. The commander's orders were that the commandos were not to endanger their health by posting lookout, by assisting the chief engineer with maintenance, or by doing anything else. They didn't have to prove themselves, and this rankled the commander and his crew.

  Colonel von Stihl was icy and seldom spoke. His blond hair was close-cropped and curly. He was average height and was barrel-chested, with thick, powerful arms and legs. Cords of neck muscle stood out even when he relaxed. He had critical eyes, severe lips, and a rather large, non-German nose. He spent much of his time aboard reading economics treatises in the petty officers' quarters. During the voyage from Germany, he had engaged in several discussions with the second watch officer, who had apparently read John Maynard Keynes, but the officer's knowledge and insights were soon exhausted. Many of the colonel's hours were spent staring catatonically at the sub's plumbing, lost in thought. After several days at sea, no one approached him.

  Von Stihl's men had also disturbed U-513's crew. The giant Hans Graf let it be known he was in the SS Death's-Head regiment and seemed pleased that none of the sailors spoke with him from then on. The skin under Graf's right ear had been badly burned, and the scar had lost none of its purple anger. It pulled back the corner of his mouth into a small grin that gave his otherwise Teutonically handsome face a perpetual evil sneer. Graf was aware of this effect and exploited it effectively on his superiors, his lovers, and those he was about to murder in the name of the Reich.

  The third stormtrooper was less sinister. In fact, Willi Lange was so inconspicuous he almost disappeared in the close confines of the U-boat. Lange was a slight man, barely reaching Graf's shoulders. He had a pug nose over a scrawny mustache. His beady black eyes never looked at the person addressing him, and his face suffered an oppressed expression, which he tried and failed to elevate to one of mere insouciance. Graf derisively called him Schwachheit, saphead. But one of Lange's peculiarities kept Graf from overpowering him and the sailors from befriending him. Lange's sole diversion aboard the sub had been to unroll the watertight oilcloth in which he kept his Schmeisser submachine gun and constantly and lovingly disassemble, clean, oil, and reassemble it. The little man even unloaded the clips and cleaned the bullets. Once, en route, when von Stihl had suggested Lange read one of his books because the cleaning was unnerving the sailors, Lange had read a chapter or so with the book resting on the mess table while his hands skillfully cleaned and recleaned the weapon. Lange's eyes never left the text, and his hands never faltered with the gun's parts. Von Stihl quickly gave up his attempts at expanding Lange's mind.