"When can I start work on fixing up the lab, Colonel?"

Hogan put aside the soup bowl. It was half an hour till lights out, and he'd just managed, by sheer force of will, to get Carter to take his first meal since the explosion the night before. It was little enough, just some of LeBeau's vegetable soup. Still, Hogan was pleased to notice a bit more color in the patient's face.

"Not yet," he said. "In the first place, you can hardly stand up, so you won't be doing anything."

"But, Colonel..."

"That's an order, Carter." Hogan cut the protest short. "You're just going to have to let the rest of us handle it. And before we even think about it, there's a lot of other work has to be done down there first. Once the tunnel's been made safe, and we've had a good look round, then we can make a start. And it could be a couple of days. We're on work detail tomorrow, repairing the Hammelburg Road."

Carter's brow wrinkled with anxiety. "Well, okay. But gee, Colonel, road maintenance is hard work. Do I have to...?

"No, Carter, you're excused." Hogan sighed unconsciously. He was trying to be patient, but sometimes Carter seemed almost wilfully obtuse. "Wilson's told Klink you're sick - pink-eye or something like that, enough to get you out of the work detail, but not serious enough for Klink to start panicking and bring in a doctor. Mills has it as well, so he'll be on hand in case Staller gets any ideas."

"Well, can't I go down and at least have a look?" Carter's fingers closed nervously, twisting the edge of the blanket. "Maybe there's some stuff can be salvaged. I could start..."

"Carter, what part of the word 'no' don't you understand?" interrupted Hogan. "Your job at the moment is to get well. That means you take it easy, until Wilson gives you the okay. Is that clear?"

"Yes, sir," muttered Carter, after a few seconds.

"Good. Now lie down, and get some sleep." Hogan went out into the main barracks, turning out the light.

Carter lay still. The throbbing pain from the cut on his forehead was such a constant presence, he hardly noticed it any more, but his other injuries made themselves felt if he moved carelessly. He had to allow the colonel was right, he wasn't in any condition to go messing about in the wreckage of the lab. But he had to do it, as soon as possible.

Hogan had made a pretty good case, the night before, for someone else - Staller, or maybe Kellet - having been responsible for what had happened. But Carter's own memory of the incident was incomplete, it ended abruptly just after he'd told Mills...well, never mind that, he didn't want to think about that.

Maybe Hogan was right, and Staller had fixed up some kind of delayed action charge. But the big jar of ammonium chlorate had been sitting right there on the workbench. The first blast going off might have triggered a second explosion, a much bigger one. And that would have been Carter's fault. The complete demolition of the lab, the cave-in, his own injuries as well as those to Mills and Kellet, all of that would be down to him.

Hogan had ordered him to take things easy. But until he'd been down to the lab, and seen for himself just how culpable he was, Carter knew he wasn't going to be able to rest.

Half after seven in the morning, straight after roll call, found the work party ready to set off for the stretch of road which had done so much damage to the Kommandant's spine. Of the inmates of Barracks 2, only Carter and Mills had been excused. But Kellet managed to fade from sight as soon as assembly was dismissed.

"Typical. The only thing he's better at than mouthing off is skiving off," remarked Newkirk. "You want me to go and chase him out, Colonel?"

"Too late," said LeBeau, jerking his head towards the truck already approaching from the motor pool.

"Better leave it," added Hogan. "We don't want the Krauts getting curious."

"Maybe if one of us stayed behind as well..." Kinch began.

Hogan considered, his eyes on the guards. "No. One man down, we might get away with, but not two. Schultz is already on edge over Staller taking Carter's place at roll call. We don't want him to go looking for absentees. Mills, you get back to the barracks, and don't let Staller out of your sight. Carter's still sleeping, he'll be safe enough as long as you're in the barracks."

"Yes, sir," murmured Mills.

He moved off quickly. Staller had already headed indoors, and even though he'd have to be crazy to risk another attempt on Carter, nobody was prepared to give him any opportunity.

"You know what I think, Colonel?" began Newkirk, but before he could complete the thought Schultz came bustling over.

"Everybody into the truck," he ordered. "No talking, and no monkey business."

"Why so grouchy, Schultz?" asked Hogan, regarding him with a lazy smile. "Get up on the wrong side of the war this morning?"

Schultz scowled at him. "Colonel Hogan," he began, then paused, glancing around to see where the other guards were. He lowered his voice before continuing. "Carter was not at roll call again this morning. Please, Colonel Hogan, you have to tell me where he is."

"Why should I, Schultz?" The smile remained on Hogan's face, but there was a shrewd look in his eye. "After all, if one of us knows, isn't that enough?"

"No," said Schultz brusquely. Then after a few seconds, he added, "Maybe."

A few more seconds passed, before he continued, "All right. But at least tell me who was that man answering for him at roll call."

"You sure you want to know?" The smile faded, but the calculating gleam remained. "Really, Schultz?"

Schultz sighed. "Get into the truck," he grumbled. "I see nothing, I hear nothing, I know..." The rest of the sentence faded into inaudibility as he lumbered away towards the cabin.

From inside the barracks, Mills watched the truck roll out through the main gate. He glanced at Staller, who was sitting on the bench beside the table, leaning on his elbows. Staller didn't look up, in fact he hardly seemed to notice he wasn't alone. Mills kept a surreptitious eye on him for a couple of minutes, but the man's face was giving nothing away.

The truck was now out of sight. Mills closed the shutters, and went to the door of Hogan's office. Carter was keeping very quiet in there, too quiet. And as Mills opened the door and looked inside, he realized why.

Oh, crap! he thought.

Carter wasn't in there. He must have sneaked out while the rest of the men were out on assembly, and Mills had a pretty good idea where he would be.

He had two choices. He could leave Carter, who could barely move without pain, to pick over the wrecked lab on his own, or he could leave Staller, still under suspicion, alone in the barracks to get up to God only knew what kind of mischief.

So, not a choice, really. Staller, left to himself, could potentially endanger the whole operation. Carter was only one man, and in spite of everything, he knew how to take care of himself. And Hogan had left Mills with one specific command: Don't let Staller out of your sight.

Mills closed the door, and went over to his own bunk. He picked up the book he'd left lying there, a battered copy of Five Red Herrings which had circulated the entire camp for the last year before finally reaching Barracks 2. It wasn't his preferred style of literature, but books were hard to come by round here, and you took what you could get. At least it would give him something to do while he watched Staller and waited for Carter to resurface. But if Carter didn't...

The barracks door opened, jolting him out of his dilemma. He noticed without really taking it in that Staller was almost as startled as he was. Both of them relaxed when they saw who it was.

"Just come to take a look at Carter," said Wilson, gazing from one man to the other in perplexity. Receiving no reply, he headed towards Hogan's quarters.

Mills put down the novel. "He's not in there. I think he's down below."

Wilson had stopped in his tracks, his shoulders dropping in a sigh of exasperation. "What's with him? I told him to stay put." He turned towards the tunnel entrance, but once again Mills stopped him.

"I better go," he said. "I know where he'll be. Just wait here a couple of minutes, I'll fetch him right up."

The medic's arrival was a lucky break. Wilson didn't know what was going on, but his presence was all that was needed to keep Staller from causing trouble. Even so, Mills didn't waste a moment. He was already at the tunnel entrance before Wilson answered, and he hardly noticed the discomfort of his injured shoulder as he went down the ladder. Grabbing a flashlight from the supply, he made straight for the lab.

He slowed down as he got close to the collapsed tunnel. The amount of work still to be done was obvious, the width of the passage almost halved by the temporary scaffolding of salvaged timbers which supported the earth above. It didn't look like it would hold up for long, and without realizing it, Mills held his breath as he proceeded.

As he had expected, he found Carter in the lab, standing quite still just inside the entrance. He'd gotten as far as picking up a piece of blackened wood, but clearly had no idea what to do with it. There was nowhere to put it down.

Mills hesitated before he spoke. "Carter, you're not supposed to be in here." Carter didn't answer, and after a few seconds Mills went on. "Wilson's in the barracks, he came to check on you."

"Yeah, okay. In a minute," replied Carter. He took a tentative step towards the center of the lab, his eyes on what was left of the workbench.

"Does something about that look funny to you?" he asked.

Mills came forward. The top of the bench had been splintered by the force of the explosion, the legs blasted in fragments to the corners of the lab. Vaguely, he recognized the lump of wood in Carter's hand as one of those pieces.

About a third of the benchtop remained where it had fallen, the rest was all over the place. Mills gazed at it, trying to see what Carter was getting at. "Is it right side up?" he asked, after a moment.

"I think so," said Carter. He handed his own flashlight to Mills, and leaned forward, awkwardly and with a soft hiss of discomfort, to put his fingertips on the jagged, upward-pointing splinters. "It's been blown up from beneath," he added. "Whatever it was, it was under the bench. It just blew it to bits."

"Well, I guess that settles it," observed Mills. "Hogan's right, there was something planted under there."

"Yeah, but..." Carter straightened up, gazing around. "What happened to the chlorate?" he went on. "It would have been right on top of the blast. Maybe it went off, too. Maybe that was why the explosion was so big. Maybe..." He broke off abruptly, his eyes falling on the remains of the workbench again. "So I guess it was partly my fault after all," he mumbled.

"Don't worry about that now," said Mills after a few seconds. "We can work that out later, when we get the place cleaned up."

"We'll never get it cleaned up." Carter's voice wavered. "I mean, look at it." He made a vague gesture towards the rest of the lab, the smashed fragments of what must have been jars and beakers, the shelves half-torn from their brackets. "I don't even know where to start. It's wrecked. I got nothing left, this was..." Once again, he stopped in mid-sentence.

"We'll fix it." But Mills, as he surveyed the damage, had doubts. He ran the flashlight beam across the debris-strewn floor, then around the walls. As it reached the furthest corner of the lab, he stopped.

"Carter," he said, his tone softening into a query.

He moved forward, stumbling a little as his feet met another piece of the workbench. The flashlight beam dropped, then came up again, illuminating the end wall, and the cabinet where the most volatile chemicals were stored. This had somehow survived the disaster, although the glass in the doors was cracked.

Mills came to a halt in front of it, and after a moment's indecision, he opened one of the doors.

"But...but that's..." Carter had followed him, and now stood staring at the big jar full of white powdery crystals which had caught Mills's attention.

"That's the chlorate," said Mills. "You must have put it back."

Carter stared at the jar, apparently petrified with disbelief. "I - I don't remember," he stammered at last.

"Well, it's there, all right." Mills glanced at him. "It was probably three or four minutes after I left before you came after me. Plenty of time to make sure everything was safe before you left the lab."

"Yeah, I guess so," murmured Carter, still bewildered. "So..."

"So the whole of the blast was down to Staller," Mills concluded. "He sure wasn't fooling around, he meant to make sure of the job. God, the bastard! "

He closed the cabinet and turned away. "We better get back to the barracks. Can't keep the medic waiting."

"I still don't get it," said Carter. "Why'd he want to do something like that?" Then, after a pause, "How'd he do it, anyway? He can't have brought the stuff with him from London."

It was a question that hadn't yet occurred to Mills, but the answer was obvious. "He had plenty of time down here on his own," he said. "He found the lab, all right. Maybe he found the munitions store as well."

There was a moment of silence, then a burst of indignation from Carter. "Well, that just takes the cake! Of all the dirty tricks...!"

"What do you mean, Carter?" asked Mills, totally confused. He'd never seen Carter really angry before. Nobody had. But this last discovery was one step too far, and Carter's eyes flashed as he answered.

"He can't do that and get away with it. If anyone's going to blow up my lab with my dynamite, it's gonna be me!"