“It depends what the questions are,” said Collings.

Helward decided to abandon trying to justify himself.

“It’s two things,” he said. “The optimum and the oath. I’m not sure about either of them.”

“That’s not surprising. I’ve worked with dozens of apprentices over the miles, and they all worry about those.”

“Can you tell me what I want to know?”

Collings shook his head. “Not about the optimum. That’s for you to discover for yourself.”

“But all I know about it is that it moves northwards. Is it an arbitrary thing?”

“It’s not arbitrary… but I can’t talk about it. I promise you that you’ll find out what you want to know very soon. But what’s the problem with the oath?”

Helward was silent for a moment.

Then he said: “If you knew I’d broken it — if you knew at this moment — you’d kill me. Is that right?”

“In theory, yes.”

“And in practice?”

“I’d worry about it for days, then probably talk to one of the other guildsmen and see what he advised. But you haven’t broken it, have you?”

“I’m not sure.”

“You’d better tell me about it.”

“All right.”

Helward started to talk about the questions Victoria had asked him at the very beginning, and tried to confine his account to vague generalities. As Collings stayed silent, Helward began to go into more and more detail. Soon he found himself recounting, almost word for word, everything he had told her.

When he had finished, Collings said: “I don’t think you’ve anything to worry about”

Helward experienced a feeling of relief, but the nagging problem could not be dispelled as quickly as that.

“Why not?”

“No harm has come of your saying anything to your wife.”

The city had come into view as they walked, and they could see the customary signs of activity around the tracks.

“But it can’t be as simple as that,” said Helward. “The oath is very firm in the way it is worded, and the penalty is hardly a light one.”

“True… but the guildsmen who are alive today inherited it. The oath was passed to us, and we pass it on. So will you in your turn. This isn’t to say the guilds agree with it, but no one has yet come up with an alternative.”

“So the guilds would like to dispense with it if possible?” said Helward.

Collings grinned at him. “That’s not what I said. The history of the city goes back a long way. The founder was a man named Francis Destaine, and it is generally believed that he introduced the oath. From what we can understand of the records of the time such a regimen of secrecy was probably desirable. But today… well, things are a little more lax.”

“But the oath continues.”

“Yes, and I think it still has a function. There are a large number of people in the city who may never know what goes on out here, and will never need to know. These are the people who are mainly concerned with the running of the city’s services. They come into contact with the people from outside the city — the transferred women, for example — and if they were to speak too freely, perhaps the true nature of the city would become common knowledge with the people outside. We already have trouble with the locals, the tooks as the militia calls them. You see, the city’s existence is a precarious one, and has to be guarded at all costs.”

“Are we in danger?”

“Not at the moment. But if there were any sabotage, the danger would be immediate and great. We’re unpopular as things stand… there’s no profit in allowing that unpopularity to be compounded with a local awareness of our vulnerability.”

“So I can be more open with Victoria?”

“Use your judgement. She’s Lerouex’s daughter, isn’t she? Sensible girl. So long as she keeps to herself whatever you tell her, I can’t see any harm. But don’t go talking to too many people.”

“I won’t,” said Helward.

“And don’t go talking about the optimum moving. It doesn’t.”

Helward looked at him in surprise. “I was told it moved.”

“You were misinformed. The optimum is stationary.”

“Then why does the city never reach it?”

“It does, from time to time,” said Collings. “But it can never stay there for long. The ground moves away southwards from it.”

2

The tracks extended about one mile to the north of the city. As Helward and Collings approached they saw one of the winch-cables being hauled out towards the stay-emplacements. Within a day or two the city would move forward again.

They led the horse over the tracks, and walked down towards the city. Here on the north side was the entrance to the dark tunnel that ran beneath the city, and which gave the only official access to the interior.

Helward walked with Collings as far as the stables.

“Goodbye, Helward.”

Helward took the proffered hand, and they shook warmly.

“You make that sound very final,” said Helward.

Collings shrugged in an off-hand way. “I shan’t be seeing you for some time. Good luck, son.”

“Where are you going?”

“I’m not going anywhere. But you are. Just take care, and make of it what you can.”

Before Helward could reply the man had turned away and hurried into the stables. For a moment Helward was tempted to go after him, but an instinct told him that it would serve no purpose. Perhaps Collings had already told him more than he should.

With mixed feelings, Helward continued down the tunnel to the elevator and waited for the car. When it arrived he went straight to the fourth level to look for Victoria. She was not in their room, so he went down to the synthetics plant to find her. She was now more than eighteen miles pregnant, but was planfling to continue working for as long as possible.

When she saw him she left her bench, and they returned to the room together. There were still two hours to spare before Helward was to see Future Clausewitz, and they passed the time with inconsequential conversation. Later, when the door was unlocked, they spent a few minutes together on the outside platform.

At the appointed time Helward went up to the seventh level, and gained access to the guild block. He was now no stranger to this part of the city, but he visited it infrequently enough to feel still slightly in awe of the senior guildsmen and Navigators.

Clausewitz was waiting in the Future guild room, and was alone. When Helward arrived he greeted him cordially, and offered him some wine.

From the Futures’ room it was possible to see through a small window towards the north of the city. Ahead, Helward could see the rising ground he had been working in during the last few days.

“You’ve settled in well, Apprentice Mann.

“Thank you, sir.”

“Do you feel ready to become a Future?”

“Yes, sir.”

“Good… from the guild’s point of view there’s no reason why you shouldn’t. You’ve earned yourself some good reports.”

“Except from the Militia,” Helward said.

“You needn’t concern yourself with that. Military life doesn’t suit everyone.”

Helward felt a small relief; his bad showing in the Militia had made him wonder if word of it had got back to his guild.

“The purpose of this interview,” Clausewitz went on, “is to tell you what is to happen next. You still have a nominal three miles’ apprenticeship to serve with our guild, but as far as I am concerned that will be a mere technicality. Before that, though, you are to leave the city. It’s a part of your training. You will probably be away for some time.”

“May I enquire for how long?” said Helward.

“It’s difficult to say. Several miles, certainly. It might be as few as ten or fifteen, or it might be as long as a hundred miles of time.”

“But Victoria—”

“Yes, I understand she’s expecting a child. When is it due?”

“In about nine miles,” said Helward.

Clausewitz frowned. “I’m afraid you will have to be away at that time. There’s really no alternative.”