Thomas returned to his cabin and enjoyed a long, dreamless sleep, awaking eight hours later much refreshed and feeling more like his old self than he had in a long time. His long chat with Matthew had done him the world of good. He didn't mind at all when the wizard unloaded all his fears and problems onto him, and he was able to give good advice, but the advice was less important than just being able to share with someone. Telling someone else about it helped him sort it all out in his own mind, and allowed him to realise that he was really worrying about nothing. "Thank the Gods for him," he said to himself as he pulled on his clothes and buttoned up his shirt. "Thank the Gods for giving me a true friend."

     He went up to the bridge to see if anything had happened and found Tana Antallan sitting alone, staring thoughtfully at the image of the ring that was still showing in the mirror. "There has been no change," the shae said in reply to his question. "The artifact appears to be moving in a slow circle about a central point, but other than that it has shown no activity."

     "No more Immortal Wizards shown up then?" said Prup Chull, wheeling himself in in his wheelchair. He'd removed most of the clothes that had swaddled him from head to foot when he'd first come aboard, perhaps because it was making him uncomfortably hot in the ship's controlled warmth, and he now wore only a single layer of thin silk, just enough to hide the loose, sagging skin that he knew humans found so unsettling. Thomas could still see muscles bulging in his thin, fragile arms, though. All this exercise in full Tharian gravity was building him up like a bodybuilder.

     "Not so far," replied the shae, "but I will breathe easier when that object has been destroyed."

     "I'm not sure it'll be possible to destroy it," said Thomas, however.

     "Why not?" asked the moon trog, sounding a little alarmed. "You think Salammis made it indestructible?"

     "No, it's not that, although he may well have done that. No, I was thinking of the dead ring we've got down in the hanger deck."

     "What about it?"

     "Well, that ring has to be the twin of that one out there. That one out there links to a ring in the past, right? But what happens to the ring in the past as the centuries go by? It must eventually end up here, in the present. Right?"

     "By the Gods, yes! You're right!" Prup stared at him in sudden comprehension. "So the ring in the hanger is that one's twin, but a thousand years older!"

     "Right! But the one in the hold was clearly not destroyed by an explosive release of magic. It appears more as if the magic leaked slowly out of it, probably over centuries. Since whatever happens to one happens to the other, it follows that that ring out there will also die slowly, probably over centuries. Any attempt by us to destroy it will, therefore, fail."

     "But, you're talking about something that hasn't happened yet," protested the moon trog. "It is said that even the Gods Themselves cannot foretell the future, so how can you, a mere mortal, predict how that ring will die?"

     "Well, this is a special case," said the wizard with a grin. "That ring exists in the present and the past at the same time, so its fate is as fixed and unchangeable as any other past event, even though, from one point of view, it hasn't happened yet."

     Prup Chull shook his head slowly. "It's beyond my poor head, so it is. Either something's happened or it hasn't. How can it be both at the same time?"

     "It is a difficult idea to grasp," admitted Thomas, who wasn't completely sure he grasped it himself, "but I'm pretty sure I'm right about it. It explains why we've got three bayta rings. There aren't three, just two, as there should be. Two of them are, in fact, the same ring."

     "If you say it is so, my friend, then I accept it to be so," said Tana, who looked more than a little confused himself. "The question, then, is how do we prevent another Immortal Wizard from coming through the ring?"

     "I don't know," admitted Thomas. "Maybe Saturn's got some idea. Is he back yet?"

     "If he has returned to the ship, he has not yet visited the bridge," said the shae.

     "If he was back, the bridge would be the first place he'd come, to see if anything's happened. He must still be back in the valley. Maybe he's decided to spend the night in his own bed rather than those instruments of torture they've given us to sleep on." He rubbed his aching shoulders, arching his back in an attempt to get the cramp out of his spine. "Where's the Coronet of Farspeaking? I'd better be wearing it in case anyone wants to talk to us."

     The message came just a few minutes later. "This is Natan Crowley," said a voice in Thomas's head. "I want to speak to Saturn."

     Thomas almost fell out of his chair in surprise. The Director himself! "Erm, isn't he there with you?" he asked hesitantly. "He went back to the valley to tell you what we've found here."

     Thomas sensed confusion and annoyance in the other man's thoughts. "He hasn't arrived yet. When did he set out?"

     "Almost ten hours ago. Er, maybe he got delayed along the way."

     "Maybe," conceded the Director, but a little sceptically. "All right, tell me what you've found up there."

     Thomas gave a brief summary of the tremendous discovery they'd made, feeling a prideful kind of delight at the astonishment he sensed in the Director's thoughts. The astonishment turned to alarm, though, when the younger wizard mentioned the appearance of Salammis.

     "You're completely sure he's dead?" Natan Crowley asked anxiously.

     "If he tried to teleport all the way back to Tharia in one go, he must be," Thomas replied, beginning to feel a little more confident. Natan Crowley had none of the fearsome aura of power that Saturn, Pondar Walton and Seskip Tonn had. He was an accomplished wizard, it was true, but basically he was just an organiser. A pen pusher. He, rather than Saturn, was the Director because no-one else could be bothered to handle the routine day to day business of running the University. Only twice in the University's history had a tyrant risen to power (although Saturn had more than a suspicion that the Head Proctor aimed to become the third, with Natan Crowley as his secretary, doing the same job he did now but as his underling). Most wizards were too busy with their own personal projects to be interested in politics.

     There was a long silence before the Director spoke again. When he did finally speak there was something in his voice that Thomas found rather disquieting. "Did you or anyone see Saturn actually enter the teleportation cubicle?" he asked.

     "Well, no," admitted Thomas, "but that's where he said he was going."

     "What was the last you saw of him?"

     "When he left the bridge. Why, what is it? You think Saturn stayed aboard? Why would he..." Thomas fell silent as the same idea came to him that had already occurred to his superior. "You think he went outside the ship? You think he went down to Tharia, to the past?"

     "I'm sending some proctors up to take charge," the Director told him. "You will give them your full co-operation. If Saturn returns before they arrive, you are to tell him to place himself under arrest."

     "What!" cried Thomas in astonishment. "But, but..." But Natan Crowley had broken the link, leaving the younger wizard worried and frightened.

     "What is it, lad?" asked Prup Chull, staring at him in concern. "Bad news?"

     Thomas repeated the conversation to him in its essentials, and as he did so he began to tremble. "He thinks he's gone through the ring," he said. "Back to the Agglemonian Empire."

     "Why would he wish to do that?" asked Tana. "And why not tell anyone?"

     "I don't know," said Thomas in confusion. "Grab a few Agglemonian souvenirs, perhaps. Gifts for his friends and... Oh, Gods! No!"

     "What?" asked Prup Chull. "What is it?"

     Tana Antallan was staring at the wizard with fear, though. "You cannot think..." He began hesitantly.

     "Think what?" demanded the moon trog. "What has he gone after?"

     "I can only think of one thing," said Thomas, his mouth suddenly dry with fear. "Something that doesn't exist in the world any more. Something that's been forbidden for centuries. The secret of immortality."