Ascar had again stood up. Heshke was alarmed to see that he had produced a gun from somewhere in his combat suit. With a cry Heshke also scrambled free of his straps and staggered forward, recklessly intending to tackle him. But at that moment Ascar lunged, seizing a handgrip on the control panel and swinging it far over. The time traveller accelerated wildly and overshot the Absolute Present to hurtle wildly futureward. The accompanying jolt sent Heshke reeling. He fell, hit his head violently against the arm of a chair, and blackness overwhelmed him.
He came round to find himself back in his seat, lolling against the straps. His head ached abominably. But the pain was soon forgotten in the horror and shock of what he saw.
The co-pilot was lying against one wall, evidently dead. The other Titan was disarmed and stood against the opposite wall, warily watching Ascar who was nonchalantly piloting the time traveller while keeping an eye on him.
“Uh – what happened?” Heshke rasped.
Ascar spared him a glance. “Welcome back. I’m afraid there was a scuffle. Lieutenant Hosk got shot. Wasn’t really my fault.” He spoke the last in a surly mumble
Heshke paused. “And the alien time traveller?”
“We lost it.” Ascar gave a tight, sinister grin. “I’ve been pushing this ship to its limit – close to a hundred and fifty years per hour.”
The words “You’re mad” died in Heshke’s throat.
“Where are we now?”
“Nearly four hundred years in the future.”
Heshke lay back in his seat, trying to fight off a feeling of hopelessness. Ascar’s mind had evidently snapped under the strain. He and the pilot would have to be patient and await their chance to overwhelm him.
“The future? What do you expect to find there?” he asked, stumbling over the words. “You said yourself it’s all dead and empty.”
“The facts are staring us in the face,” Ascar replied. “That’s the mark of the true scientist, isn’t it, Heshke? To take facts as facts even if they conflict with theory, and draw the most obvious deductions from them. That’s what we’ve been failing to do.”
“What facts are those?” Heshke glanced nervously at the Titan, who was watching Ascar warily.
“Chiefly, the plain fact that the alien interventionist ruins are ageing backward in time. If we take that at face value, then their source lies in the future, and we’re going to track it down.”
His words were interrupted by the sounding of the gong. The Absolute Present register began to glow, for the second time this trip.
“There she blows!” crowed Ascar.
The Titan’s jaw dropped. He stared at the register as though unable to believe his eyes.
“But we’re four centuries away from Absolute Present!”
“Four centuries from our Absolute Present.”
“There is only one,” the Titan insisted emptily. “Your own equations say so… you to whom we owe the secret of the time-drive…”
“Well, I can’t be right all the time,” Ascar said, rather bleakly. “What do you think I was doing for three hours while we made the journey back – just sitting there with a blank mind?” He snorted. “Oh no, I was going over those very equations you seem to regard as sacrosanct… and it occurred to me that I might not know as much about time as I had thought, and that the equations could be wrong. So I began to imagine a number of other possibilities. What if the Absolute Present isn’t unique, as I had formerly assumed it to be? Perhaps there are other waves of time, separated from our own by millions of years, by millennia – or only by centuries. Perhaps there is a regular series of them, forming the nodes of a cosmic wave frequency vibrating through the universe. Whatever the truth, I discovered that if I amended the equations to make room for any of these possibilities then the basic principle that makes the time-drive work remains unchanged… so the theoretical structure had to give way… even if the Great Earth Mother has to give way too.…”
While he spoke Ascar had been deftly flying the time traveller, dividing his attention between the instruments and his two hijacked passengers. His gun was never more than an inch or two away from his right hand.
He continued ramblingly. “And what if one of those other time waves was travelling in the opposite direction to our own? Not proceeding from the past into the future, as we understand time, but from the future into the past? The very words past and future tend to lose their meaning in such a context.… Whatever lies behind one’s direction of motion is the past and whatever lies in front of it is the future.… There it is!”
His last words were a shout, an excited squawk. The Absolute Present register had zeroed in and stood slightly on the other side of zero.
Ascar turned a knob, tuning the windows to transparency. “Take a look,” he said. “We’re at time-stop.”
Slowly Heshke rose and approached one of the windows.
It was Earth, but it was not Earth. The sky was blue, with white clouds hanging majestically in it. The sun was of a familiar size, colour and radiance. But there the resemblance ended. True, there was grass – green grass… but it was an olive green shot through with mother-of-pearl colours, and all the other vegetation was distinctly non-Terran; the trees – twisted, writhing things – bore no resemblance to any Earth tree that had ever existed as far as Heshke knew.
These trees, growing on the slope of a grassy eminence where Ascar had set them down, did not detain his attention for long. Briefly he noted an unrecognisable flying thing, frozen in midair as had been the raven, and then he flooded his vision with the incredible scene that was set out below.
The Hathar Ruins: but not the ruins that Heshke had studied for so many years, and not those still further back down the centuries. This was the Hathar site as it had been in its prime: an intact, inhabited settlement. He drank in the clean-cut, sparkling conical towers, the large buildings, the Cathedral (whose purpose he still did not know), the tenement-like masses of smaller rooms, the plazas, the roads.…
It was all as he had constructed it in his imagination so many times. Alien, but alive. A bustling, living habitation of a nonhuman people.
And those people thronged Hathar. Furry, sharp-snouted, standing in triangular doorways and walking the streets and squares. But they were caught in mid-motion like a stereo still photograph: the traveller was not moving in any direction in time.
“The alien interventionists!” breathed the Titan officer. Both he and Heshke had forgotten their tacit agreement to jump Ascar.
“Correct. But they are not interventionists, though they are alien in a sense.”
The Titan clenched his fists. “So we have been mistaken all along. The enemy is attacking from the future. That must be where he made his landings on Earth.”
“No, no,” said Ascar, adopting a tone of uncharacteristic patience. “Watch this: I’m putting us in motion again at the biological rate of one second per second.”
He made an adjustment. The scene came to life. The clouds sailed across the sky, the trees moved, the aliens walked through streets and squares.
“They’re walking backward,” said Heshke blankly.
And so indeed they were. The whole scene was like a motion picture thrown into reverse. “That’s because we’ve adopted the time sense normal to us,” Ascar explained, “but it’s not normal to them. Now watch what happens when I put our machine into reverse at the same rate – one second per second.”
Again he made an adjustment. They all watched through the windows while the scene rewound itself and went forward, the alien creatures walking naturally this time, with a rolling gait, their posture not quite as erect as that of a human being. “This is their normal time-sense,” Ascar told them, “the reverse of ours. Now do you get it? These creatures aren’t alien to Earth. They’re Terran. They evolved here, millions of years in our future. By the same token, we are in their future. The Earth has two completely different evolutionary developments on it, separated in time and associated with separate time-streams – time-streams moving in opposite directions. And they are on a collision course.”