The morning traffic had been forced to make way for the thing; two dog-carts lay overturned in the road ahead of it, as did a brewer’s dray, with a distressed horse still caught between the shafts, and beer spilling from broken barrels.

One youth in a cap, foolhardy, hurled a lump of churned-up cobble at the thing’s metal hide. The stone bounced off the hull without leaving so much as a scratch, but there was a response: I saw a rifle poke its snout out of one of those upper ports, and fire off with a crack at the youth.

He fell where he had stood, and lay still.

At that, the crowd dispersed quickly, and there were more screams. Mrs. Penforth seemed to be weeping into her duster; Poole escorted her into the house.

A hatch in the front of the land ironclad opened with a clang — I caught a brief impression of a dim interior — and I saw a face (I thought masked) peer out towards us.

“It is Out of Time,” Nebogipfel said. “And it has come for us.

“Indeed.” I turned to Moses. “Well,” I said to him. “Now do you believe me?”

Moses’s grin was tight and nervous, his face paler than usual and his broad brow slick with sweat. “Evidently you are not the only Time Traveler!”

The mobile fort — if that was what it was — toiled its way up the road towards my house. It was a long, flat box, with something of the aspect of a dish-cover. It was painted in patches of green and mud-brown, as if its natural habitat were some broken-up field. There was a skirt of metal around its base, perhaps to shield its more vulnerable parts from the rifle-shots and shrapnel of opponents. I should say the fort was moving at around six miles per hour, and — thanks to some novel method of locomotion whose details I could not make out, because of that skirt — it managed to keep itself pretty level, in spite of the Hill’s incline.

Save for the three of us — and that wretched brewer’s horse — there was not a living soul left in the road now, and there was a silence broken only by the deep grumbling of the fort’s engines, and the distressed whinnying of the trapped horse.

“I don’t remember this,” I told Nebogipfel. “Any of it this didn’t happen, in my 1873.”

The Morlock studied the approaching fort through his goggles. “Once again,” he said evenly, “we have to consider the possibility of a Multiplicity of Histories. You have seen more than one version of A.D. 657,208: now, it seems, you must endure new variants on your own century.”

The fort came to a halt, its engine growling like some immense stomach; I could see masked faces peering out from the various ports at us, and a pennant fluttered languid above its hull.

“Do you think we can run for it?” Moses hissed.

“I doubt it. See the rifle-barrels protruding from those portholes? I don’t know what the game is here — but these people clearly have the means, and the will, to detain us.

“Let’s show a little dignity. We will go forward,” I said. “Let us demonstrate we are not afraid.”

And so we stepped out, across the mundane cobbles of the Petersham Road, towards the fort.

The various rifles and heavier guns tracked us as we walked, and masked faces — some using field-glasses — marked our progress.

As we neared the fort, I got a better view of its general layout. As I have said it was more than eighty feet long, and perhaps ten feet tall; the flanks looked like sheets of thick gun-metal, although the arrangement of ports and scopes at the fort’s upper rim gave it a mottled impression there. Jets of steam squirted into the air from the rear of the machine. I have mentioned the footfall skirt which surrounded the base; now I was able to see that the skirt was lifted away from the ground, and that the machine stood — not on wheels, as I had assumed — but on feet! These were flat, broad things, about the shape of elephant’s feet, but much larger; from the indentations they left in the road behind, I could infer that the lower surfaces of these feet must be grooved for traction. This arrangement of feet was, I realized now, how the fort was keeping itself more-or-less level on the slope of the road.

There was a device like a flail fixed to the front of the fort: it consisted of lengths of heavy chain attached to a drum, which was held out on two metal frames before the fort’s prow. The drum was held up, so that the chains dangled in the air, like carters’ whips, and they made an odd clanking noise as the fort traveled along; but the drum was clearly capable of being lowered, to allow the chains to beat against the ground as the fort advanced. I could not fathom the purpose of this arrangement.

We stopped perhaps ten yards from the blunt prow of the machine. Those rifle-men kept their muzzles trained on us. Steam wafted towards us, on a stray breeze.

I was suffering a deep horror at this latest unremembered turn of events. Now, it seemed, even my past was no longer a place of reliability and stability: even that was subject to change, at the whims of Time Travelers! I had no escape from the influence of the Time Machine: it was as if, once invented, its ramifications were spreading into past and future, like ripples from a stone thrown into the placid River of Time.

“I think it’s British,” Moses said, breaking into my introspection.

“What? Why do you say that?”

“Do you think that’s a regimental badge, there above the skirt?”

I peered more closely; evidently Moses’s eyes were sharper than mine. I’ve never been much interested in military paraphernalia, but it looked as if Moses might be right.

Now he was reading off other bits of text, stenciled in black on that formidable hull. “ ’Live Munitions,’ “ he read. “ ’Fuel Access.’ It’s either British colonial or American — and from a future close enough that the language hasn’t changed much.”

There was a scrape of metal on metal. I saw that a wheel, set in one flank of the fort, was turning. When the wheel was fully turned, a hatch-door was pushed open — its polished metal rim gleamed against the dun hull — and I caught a glimpse of a dark interior, like a cave of steel.

A rope-ladder was dropped down from the frame. A trooper clambered out and came walking up the road towards us. He wore a heavy canvas suit; sewn up into one piece; it was open at the neck, and I could see a lining of khaki cloth. There were spectacularly huge metal epaulets across his shoulders. He wore a black beret, with a regimental badge affixed to the front. He carried a pistol in a web holster which dangled before him; there was a small pouch above this, evidently for ammunition. I saw how the holster flap was open, and his gloved hands never strayed far from his weapon.

And — most striking of all — the trooper’s face was hidden by the most extraordinary mask: with wide, blackened goggles and a muzzle like the proboscis of a fly over the mouth, the mask enclosed the head beneath the beret.

“Great Scott,” Moses whispered to me. “What a vision.”

“Indeed,” I said grimly, for I had seen the significance of this apparition immediately. “He has protection against gas — see that? There is not a square inch of the fellow’s bare flesh showing. And those epaulets must be to protect him against darts, perhaps also bearing poison — I wonder what other layers of protection he is wearing under that bulky canvas.

“What kind of Age believes it necessary to send such a brute as this, back through time to the innocence of 1873? Moses, this fort comes to us from a very dark future — a Future of War!”

The trooper stepped a little closer to us. In clipped tones — which were muffled by the mask, but were otherwise absolutely characteristic of the Officers’ class — he called out a challenge to us, in a language which, at first, I failed to recognize.