Oh, fucking wonderful, and there I was thinking you were getting brighter.

The uproar all around continued, as Polly waited for the sword stroke that would take off her head, and almost not caring. When it died down, she glanced up to see the Emperor had raised his hand again. As he addressed his men, it was evident some of them found him incomprehensible, so badly was he stammering. When he gestured Polly to rise, she did so quickly.

‘Can you tell me how to say, “He is alive”?’ she subvocalized.

Try ‘Vivit.’

Polly gestured to the prostrate soldier, and repeated Nandru’s words. Claudius, his expression frightened, spat an order and swords were immediately sheathed.

‘That seemed to work,’ said Polly cheerfully.

Well, they haven’t nailed you to a tree yet, so that’s a plus.

The soldiers loaded walnut crusher onto the litter, and he was rapidly born back to the encampment. Polly followed on foot beside the limping Emperor.

Tack was foolishly pleased to be given the honour of addressing Traveller by his true name, though Saphothere was a mouthful to someone from an age when appellations of more than two syllables were considered excessive.

‘Saphothere.’ He tried it out. ‘What was that weapon you used on their fence?’ he asked, staring into the darkness outside the cave mouth.

Saphothere turned on some kind of palm torch to illuminate the interior beyond. ‘Molecular catalyser. The palisade was constructed of a steel composite and ceramoplastic. The catalyser caused them to react with each other: the iron in the steel combined with the oxygen in the organic molecules of the plastic, turning the fence into a powder consisting mainly of iron oxide and carbon.’ He glanced at Tack. ‘Understand, Tack, I have given you permission to use my name, but you will also use my title. The correct form of address is “Traveller Saphothere”. Your actions at the Umbrathane stronghold were admirable, but they do not entitle you to over familiarity.’

Tack grimaced as he followed Saphothere deeper inside. Studying the cave floor, he spotted broken bones and the skull of some bovid that had been crushed by the large teeth of a predator, and was grateful that Traveller had retrieved and returned his seeker gun.

‘What period are we in now… Traveller Saphothere?’

Saphothere looked at him askance, perhaps regretting the leeway he had granted. ‘It’s the Palaeocene—sixty-three million years in your past. There are not so many large animals around just now, as an extinction event occurred not long ago in evolutionary terms.’ The man then noticed the direction of Tack’s attention and added, ‘Some carnivorous dinosaurs did survive, but they will not survive the coming competition with the mammals.’ At that moment Saphothere’s torch revealed something that—like Pig City—did not belong here: a steel door.

‘They knew of you: Coptic and Meelan. She spoke your name when they saw you running towards them… Traveller.’

With no evident movement from Saphothere, the round door suddenly released from its surrounding metal frame and hissed inwards, revealing a well-lit room stacked with equipment.

‘The Umbrathane should know my name—for most of my life I’ve been hunting and killing them across half a billion years.’

Saphothere led the way past the stored equipment and into a spartan living area. Here, there were rough wooden chairs around a table, bunks for four people, equipment that might have been equally domestic or the control system for launching atomic weapons for all Tack knew, and supply boxes containing packets of food and drink. Saphothere touched a console as he walked past it, and a horizontal bar rose above it, dragging up behind it a screen of translucent film on which image-enhanced exterior scenes were instantly displayed, along with scrolling pictographic script and mobile Euclidian shapes that meant nothing to Tack.

Glancing towards him, Saphothere explained, ‘Security system—but of an order of magnitude more efficient than the pathetic one that guarded Pig City.’ He dropped into a seat and rubbed his eyes. ‘Getting to that place was more difficult than destroying it. I hadn’t realized they had so much energy to squander.’

Tack dropped against a wall the pack that had belonged to Coptic and Meelan. Saphothere, after already checking through its contents, had returned it to him with the injunction not to use any of the more complex devices it contained without instruction. Still eyeing the pack possessively, Tack took a seat on the other side of the table.

‘I don’t understand,’ Tack began.

Saphothere looked up. ‘Those enteledonts were from twenty million years in the future, and by establishing them as guards, the Umbrathane pushed their city far downslope. It has been difficult for me to bring us back to the main line. To reach here we travelled sideways in time.’ Saphothere was studying him carefully, perhaps waiting for questions his explanation would no doubt provoke from a linear mind.

But Tack understood. ‘Where did they get their energy from?’ he asked instead.

Saphothere nodded in approval. ‘They used fusion reactors dismounted from their spaceships, and perhaps some sort of parasitism on the wormhole. Easy enough, as energy is projected along it from New London all the time—it’s what our mantisals recharge from, mostly—and its available abundance in the ages between there and Sauros is the reason we were able to jump so accurately to here.’ Saphothere gestured at their surroundings. Then with a nasty smile he added, ‘Though such accurate time-shifting raises the danger of running into yourself, which would cause a short-circuit paradox—something you could only risk inside the temporal barriers of somewhere like Sauros.’

Tack absorbed this for a moment then asked, ‘So the time tunnel, the wormhole, is a conduit for this energy… the energy you all use?’

‘You might say that. Better to say, though, that the time tunnel is the energy—it’s comprised of that.’

Tack nodded slowly. He understood only a fraction of this now, but hoped to grasp more as his relationship with Saphothere progressed. He no longer felt desperate for immediate answers now he knew they would be forthcoming anyway.

‘You need food and rest now,’ Tack said, gesturing to the nearby stocks. ‘That’s food?’

‘It is, but I’ll have to show you how—’

‘I’ll learn,’ said Tack, standing up. And Saphothere was too tired himself to even be annoyed about the interruption. He rested his forehead on his arms, while Tack taught himself how to cook with the alien equipment. Finally he brought a lavish meal to the table, and they ate in silence, Saphothere growing visibly stronger with each mouthful he consumed. When they had finished, Saphothere got up and brought a bottle of amber liquid and two glasses to the table.

‘One of the better products of your time… well… quite near to your time. In the nineteenth century Sauros sat for a while in the sea underneath the Arctic ice cap. I managed to acquire five or six crates of this before our next shift. I don’t have much left now,’ he explained.

Tack and Traveller proceeded to drink malt whisky—for Tack a first-ever experience.

The Emperor was persistent in his attempts at communicating, the watcher noted. He sat impatiently on the edge of his couch, rather than reclining on it like his subordinates did on theirs. But the words were becoming increasingly mangled in his mouth as the wine flowed, and Polly was unsurprisingly showing signs of confusion, despite the fact that the AI device she carried was obviously offering some sort of translation. Perhaps it could not explain to her why the Romans seemed both excited and scared upon hearing her name. The watcher herself ran a search through her own database and came to the conclusion that this was because of its similarity to ‘Apollyon’—the Greek name for the Lord of the Abyss, Satan.