Stephen crawled back to where he had left Jack. He found him curled up and shivering. He took him by the shoulder and tried to shake him awake. Jack shouted incoherently. It sounded to Stephen as though he was saying something about a shield.

Slowly Stephen was able to restore him to himself. He rocked him gently and called his name. He felt cruel bringing him back to the facts of his Jack looked up at him imploringly, as though asking him to disappear. Stephen knew that to Jack his face was a reminder that he was still alive.

"Listen," he said. "I found a sandbag up there. What do you think that means?"

"A full one?"

"Yes."

Jack shook his head weakly. He did not respond. Stephen took him by the wrists and squeezed them. He put his face close to Jack's, where he smelt the rotten air that he expelled from his lungs.

"Is it just to sh.o.r.e up the wall, or what? What do you people use them for? Come on. Answer me. Say something." The flat explosion of his hand against Jack's face made a magnified sound in the narrow s.p.a.ce.

"I don't know... I don't know... It's just a bag. We used to fill them when we dug the tube. The Central Line. Inside the big shield. We stopped at Bank."

"For G.o.d's sake. Listen. Why sandbags in the wall? Here in France, in the war, not in the underground railway."

"We got to Liverpool Street in nineteen twelve. I was all in. Didn't work again."

Jack went on about his work in the London clay. Stephen let go of his wrists so that his arms fell on to his lifeless legs. The pain of the impact seemed to startle Jack.

He looked up again with wild eyes. "Behind the chamber. We packed them in behind the charge."

"But it's a fighting tunnel," said Stephen. "Anyway, they go sideways." Jack let out a snort. "Sideways? You're mad."

Stephen lifted Jack's hands again. "Listen, Jack. I may be mad. Maybe we both are. But we are going to die very soon. Before you go, just think very hard. Do that for me. I have carried you this far. Now do me this favour. Think what it might mean."

He held Jack's eyes in his from what light remained in the lantern. He could see Jack fighting to be free of him, desperate to shake off his last contact with the living world. Jack shook his head, or rather allowed it to loll from side to side. He closed his eyes and lay back against the tunnel wall.

There was drool and foam at the corners of his mouth. His blank, unemotional face seemed to withdraw further. Then a flicker caught the edge of his eye.

"Unless... no... unless it's Kiwis. Could be Kiwis."

"What are you talking about? Kiwis? What do you mean?"

"They lay the bags different, the New Zealanders. We stick them in a straight line behind the charge. They dig a little run at right angles to the main drive, then stick the charge in there. You don't need so many bags of spoil."

"I don't understand. You mean they'd lay a charge not in the main tunnel but off to one side?"

"That's it. Better compression, they say. Not so much work, if you ask me. Not so many bags."

Stephen tried to contain his excitement. "What you're saying is that there could be explosive in there, behind all the sandbags?"

Jack finally looked him in the eye. "It's possible. We don't come down so often these days and I know there was a Kiwi company here before us,"

"You mean they didn't tell you there was an explosives chamber?"

"They would have told the captain, but he wouldn't necessarily tell me. They never tell me anything. I've only been underground twice since we've been here."

"And then because we're not going to blow any more mines we've just been using it as a fighting tunnel to protect the main listening chamber?"

"We haven't blown a mine for months. We only do fatigues these days."

"All right. Just suppose there was explosive in a chamber behind those bags. Could we blow it?"

"We'd need wires or a fuse. And it depends how much there was. Probably bring down half the country."

"We've got nothing else to try, have we?"

Jack looked down again. "I just want to die in peace."

Stephen knelt down and lifted Jack to a crouching position, then heaved him on to his shoulder and began to stumble back into the darkness, the torch gripped between his teeth. A new energy made him unaware of the ache of his limbs or Jack's weight, or even the torturing thirst in his mouth.

When they got back to the enlarged area where he had found the sandbags, he laid Jack down again. He desperately wanted Jack to survive so that he could tell him how to blow the charge.

Each sandbag was three feet long and two feet across. They had been packed densely with what Jack called spoil, the debris of digging, in order to maximize their ability to contain the blast. With only one good hand to pull them, Stephen worked very slowly, each drag of about six inches being followed by a rest. He talked to Jack as he worked, hoping that his voice would stop him from slipping away. There was no response from the figure slumped on the ground. Although progress was measured in inches, he worked with a fury given him by hope. He had a picture in his mind of a great crater being blown into the field above them, and of him and Jack emerging from behind their shelter of sandbags to walk into the bottom of it, which, though thirty feet below ground level, would be open to the rain and the wind.

He was able to stand up in the enlarged area of tunnel and stretch his back from time to time. Each time he rested he bent over Jack and tried to rouse him with a mixture of force and cajoling. There was usually some response, though it was grudging and incoherent; he seemed to be delirious again.

Stephen went back to his work. He switched off the torch and laboured in the darkness. When he had cleared a dozen bags and stacked them in the main tunnel, it became easier to work because there was more s.p.a.ce around him. He wanted to stop and make sure Jack was still all right, but feared that the more time he wasted by not clearing the bags, the closer they would come to the end of Jack's life. He pressed on. When his left hand was not strong enough he gripped the nozzle of a wedged bag between his teeth and worried it like a terrier. A piece of chalk broke one of his front teeth and drove into his gum, filling his mouth with blood. He was barely aware of the discomfort as he worked on and eventually came to the end of the pile of bags that had been so neatly and tightly stacked by the New Zealanders.

He went back into the tunnel and took the torch from the floor. Crawling back through the s.p.a.ce he had cleared, he held the light ahead of him. There were several stacks of boxes marked "Danger. High Explosive. Ammonium Nitrate/Aluminium." They were piled against the forward wall of the small chamber, toward the enemy.

A small leap of excitement went through him. He stopped for a moment and found that his eyes were moist. He allowed himself to give in to the sensation of hope. He would be free.

He went carefully back and took Jack by the hand.

"Wake up," he said. "I'm through. I've found the explosive. We can get out. We can be free. You're going to live."

Jack's eyes, with their heavy lids, opened over his narrow, uninquisitive gaze.

"What's in there, then?"

"Boxes of ammonal."

"How many?"

"I didn't count. Maybe two hundred."

Jack let out a snort. He began to laugh, but seemed to lack the strength.

"That's ten thousand pounds. It takes one pound to blow up the Mansion House."

"Then we'll have to shift them out and just leave however much we want."

"One box would let them know we're here."

"Help me, Jack."

"I can't. I can't move my--"

"I know. Just encourage me. Tell me it can be done."

"All right. Do it. Perhaps you can. You're mad enough." When Stephen had rested for half an hour, he crawled back into the hole.

The wooden boxes had rope handles. At fifty pounds each, they were the ideal weight to be lifted and stacked by a fit man with both arms. With only his left to use, Stephen struggled badly. The ones he pulled from the top of the pile had to be jerked clear, then held aloft to stop them banging into the ground. After the first hour he had cleared six boxes and taken them back down to the fighting tunnel to a distance he imagined would make them safe from sympathetic detonation. He took out his watch and calculated. It would take him approximately thirty hours. As he became more tired and dehydrated his rests would become longer. He would need to sleep.

He looked at Jack's prostrate form on the tunnel floor and asked himself if the effort was really worthwhile. He expected Jack to die before he could finish. He could not be sure that he himself would last. At least he had found air in the explosive chamber. It was neither fresh nor plentiful, but a small trickle was penetrating from somewhere. It was possible that the explosion had smashed a ventilation pipe. There was a small pool of water on the floor in one corner which he sucked into his mouth, held, and spat back on to the chalky ground. It was too fetid to swallow, and in any case he would need it again.

In the middle of the boxes was a large wad of guncotton attached to a wire, which Stephen set to one side. When he had moved forty boxes he lay down next to Jack and slept. The time on his watch said ten past two, but he did not know if it was morning or afternoon or how long they had been underground.

He used the torch as little as possible. He worked with the instinct of an animal, brutal, stupid, blind. He did not think about what he did or why he did it. His life on the surface of the earth was closed to him. He would not have remembered Gray or Weir, could not have recalled the names of Jeanne or Isabelle. They had gone into his unconscious, and what he lived was like a b.e.s.t.i.a.l dream. Sometimes he stumbled on Jack as he pa.s.sed, sometimes he kicked him hard enough to make him respond. Occasionally he dropped to his knees and sucked at the puddle on the floor.

As he neared the end of the task he feared that he might die before it was completed. He slowed down and rested more. He checked his own pulse. It took him three days to clear the chamber and when he finished he was too exhausted to think about setting off the single box that remained. He lay down and slept. When he awoke he at once went over to Jack and shone the torch in his face. His eyes were open and fixed ahead of him. Stephen shook him, certain that he was dead. Jack groaned in protest at being brought back to wakefulness. Stephen told him he had cleared the chamber. To encourage him, he crawled into it, scooped a handful of water from the puddle, brought it carefully back in his hands, and threw it in Jack's face.

"Tell me how to blow it, and you'll have as much water as you want." Jack's voice was almost inaudible. Stephen had to put his ear close to the dry_ _lips. Jack told him they used electric leads.

"Can I do it with a fuse?"

"If you can make one. Must be long. So we can get clear."

"Suppose I used the sandbags. Tore them into strips, then tied them together."

"If they're dry. But it won't work without a primer. Ammonal burns but it won't explode without guncotton to set it off."

Stephen went down to where he had stacked the bags; they were reasonably dry. He went back to where he had left his tunic and took out his knife and a box of matches. He cut the end from a bag and emptied it, then struck a match. The ragged edge flared up and the denser parts burned slowly. It could not be relied on.

"Suppose I break a box of ammonal and lay a small trail of powder along the top of it. Would that help?"

Jack smiled. "Be careful."

"How far away do we have to be?"

"A hundred yards. Behind a solid wall. And it lets off gas. You'll need to get the breathing sets."

Stephen calculated how long it would take him to cut and tie a hundred yards of sandbag. It was not possible. He could not use the dry gun-cotton because without it the ammonal would not detonate. He would have to lay a trail of explosive.

First he carried Jack back down the fighting tunnel to the lateral gallery. He put him a few yards up the left-hand fighting tunnel where he gauged he would be best protected. He collected the Proto breathing sets from the site of the second explosion and returned with them to Jack.

Then he carefully levered the top off a box of ammonal, first with the blade, then with the handle of his knife. He took the grey powder out in handfuls and placed it in a sandbag until the bag began to grow heavy. He carried it to the chamber and emptied a pile of it against the guncotton primer, which he placed inside the box that remained. Then he laid a trail about two inches wide back through the connecting run into the fighting tunnel. By this time the bag was empty and he went back to replenish it, then returned to where he had left off and continued, twice refilling the bag, before he came to where the rest of the ammonal was stacked. He ran the trail as far from it as possible. It was a chance he would have to take: he could not move it all again. He stopped the powder in the middle of the lateral gallery. He then emptied and cut up six sandbags for a fuse to get from himself to the start of the ammonal.

He sat down next to Jack. He fitted Jack's breathing set for him, then his own. Absurd hope made his heart pound.

"This is it," he said. "I'm going to blow it."

Jack made no response, so Stephen went into the gallery and knelt down by the end of the fuse he had made from the sandbags, which was about thirty feet long. He wanted to watch it burn through to the ammonal, then he would know they were going to be all right.

He paused for a moment and tried to find some thought or prayer appropriate to the end of his life, but his mind was too tired and his hand too eager. He scratched the head of the match against the box and watched it flare. No thought of caution or fear was in his mind. He touched the sandbag and saw it flame. His heart leapt with it; he wanted to live. It made him laugh, mad-eyed and bearded, like a hermit in his cave.

The material spluttered and glowed, then caught and faded, then burned again. It went to about six feet from the end, then seemed to stop. Stephen cursed loudly. He clasped the torch. For Christ's sake. A spark flew from the dead fuse like electricity leaping in a void. It touched the ammonal and Stephen saw a sheet of flame rising to the tunnel roof. He turned and ran three steps back toward Jack, but before he got there he was pitched forward by an explosion that tore out tunnels, walls, and earth and hurled the debris up into the air above the ground. The force of the blast rocked Lieutenant Levi on the firestep, where he was eating pea soup with sausage and bread dispensed from a company cooker that had traveled hundreds of miles since its first dispatch from Saxony.

A British bombardment had been focused on their front line for three days, presumably presaging a large attack. Levi had been vaguely wondering how soon it would be before he could resume his peacetime medical practice in Hamburg, where he had begun to gain some reputation as a doctor specializing in children's ailments. He had resisted joining the army for as long as possible, but the heavy loss of life inflicted on his country had made it inevitable. He left the children in the hospital and went home to say good-bye to his wife.

"I don't want to fight the French," he told her, "and I particularly don't want to fight the English. But this is my country and our home. I must do my duty." She gave him a Star of David, a small gold one that had belonged to several generations of her family, and put it on a chain around his neck. It was not just the Jewish quarter that was sorry to see Dr. Levi go: a small crowd gathered at the station to see him off.

Since the German spring offensive had been halted and the enemy, reinforced now by the Americans, had been moving numbers of tanks up into their front lines, Levi a.s.sumed that with the bombardment under way it would be only a matter of weeks before he and his wife were reunited. The small shame he felt at the prospect of German defeat was easily outweighed by his pleasure at the thought of peace.

"You're a doctor at home, aren't you, Levi?" said his company commander, coming down the trench as the shock of the ammonal explosion began to subside.

"A children's doctor, but I--"

"All the same. You'd better go and have a look. We've got a patrol down there. Take two men with you. Kroger and Lamm. They're your best bet. They know all the tunnels here."

"There are usually two explosions, aren't there? Hadn't we better wait?"

"Give it an hour. Then go down."

Kroger and Lamm came to report to him thirty minutes later. Kroger was a refined and clever man who had refused promotion on several occasions. He came from a good family, but had principles about social justice. Lamm was of simpler, Bavarian stock, a handsome dark-haired miner of imperturbable temperament. They took breathing apparatus, in case the explosion had released gas underground, as well as picks, ropes, and other pieces of equipment Lamm told them might be useful. Lamm himself also took a small quant.i.ty of explosive.

"How many of our men were down there?" said Levi.

"Three," said Lamm. "They'd just gone on a routine patrol to listen for enemy activity."

"I thought we'd destroyed their tunnel three or four days ago."

"We probably did. We're listening to see when they're going to attack. We don't expect them to be able to repair their own tunnel. We blew it in two places. They never heard us coming."

Kroger said, "Let's go, shall we? I'd rather be underground than sitting beneath this bombardment."

They heard sh.e.l.ls screaming overhead and detonating in the support lines behind them. Levi followed the others down an incline that slowly took them thirty feet beneath the ground. Although he felt safer where the sh.e.l.ls could not reach him, he was not enthusiastic about the idea of being shut in beneath the earth. They had been issued with enough food and water to last for three days, so someone at least presumed it might be a lengthy operation.

They walked along the main gallery for ten minutes. It had electric light in the ceiling though the circuit had been broken by the explosion. The system had been built with considerable care and precision. Lamm and Kroger sang as they walked along. The tunnels followed a similar pattern to those built by the British, though the main lateral gallery of the German network was attached to the sewers of the nearby town. The listening post that they had created close to the British line was protected by a single fighting tunnel that ran about ten feet above the British works; from this they had been able to dig down and lay the two charges that had made most of the enemy system impa.s.sable.

They had not gone far up their own central tunnel before they came to a substantial blockage. Levi sat down while Lamm and Kroger explored it with their picks. An appalling thought had occurred to him. His brother, an engineer attached to the same company, had told him he expected to go down and inspect the system at some time to make sure they had effectively closed the British tunnel. He did not normally go underground, but would periodically inspect new works. Levi had not seen him for three days, which was not in itself unusual as their duties were quite different, and while he did not know that he was one of the patrol who had gone down, he did not know for sure that he was not.

"It's a very heavy blockage," said Lamm. "Our best bet is to leave it for the time being and go and see what's happened in the fighting tunnel. We can come back if we have to."

Levi said, "Do you know which men were in the patrol?"

"No," said Lamm. "Do you?"

"No, I don't. I know there are three. I'm just wondering if one of them's my brother."

Kroger said, "I'm sure the CO would have told you."

"I doubt it," said Levi. "He's got other things on his mind. He's about to be organizing a full-scale retreat."

"We'll just have to hope," said Kroger. "For all we know they're all alive anyway, just carrying on with their job."