Hobbes took them to the mouth of another large tunnel that sloped down into more darkness.
He stood at the lip and beckoned everyone to do the same and shine their torches down to where the escalator once ran.
"There, see that. Incredibly rare archaeology just ripped out or flattened, and for what?"
There was much less plant life on this slope than there had been on the other. Less water too. As a result, the decay to the ancient engineering was considerably less.
There were even places, picked out by individual probing beams of light, that showed the aluminium sides of the escalator troughs,
once shiny but now white and pitted from traces of salt in the air. The tunnel walls themselves still had large areas of tiling and smooth concrete.
At the bottom of the escalator troughs, though heavily rusted, there was even still the stumps of the machinery that had lived under the moving steps.
It was this that Hobbes was so upset about, even Bodil cringed at the damage that had been done. Large parts of the machinery had been ripped out and dumped to one side.
Now, where it once stood, stepped plascrete walkways had been installed down the whole length of one trough and a smooth plascrete slide down the other.
"It's good, Miss. It means you won't be falling on your ass as much and so I won't have to catch you as much."
"Greggie? You're fired."
The grin broadened.
Bodil watched the little interaction with a smile of her own. Their casual back and forth suggested a comfortable familiarity of long-standing.
Weis' head popped up.
"Can we get on? It's bin two hours wiv no tea break, and I don't fancy supping me brew when there's still those blood-sucking little buggers around ready to nibble on me ginger nuts.
" Having made his feelings known, Weis set off down the steps.
Hobbes sighed at the total disregard for history and followed the little ranger.
Then Gregor, then Bodil and finally, with a glance over her shoulder, Ellie brought up the rear where nobody could see her chewing worriedly on her lip.
The descent to the level of the Central Line was uneventful. By the time they reached the concourse at the bottom, the dancing torch beams were picking out very little in the way of plant life.
Yes, there was some ceiling collapse and there was a relatively large pool of water being fed by sporadic drips from another great crack directly above them, but on the whole,
the condition of the concourse wasn't too bad. There were even the remains of light fittings, long since fallen from the ceiling and now laying smashed on the tiles.
There were also more signs of manmade damage. More plascrete tracking, more post holes.
The party followed Hobbes past all this to the start of another maze of narrow tunnels and stone steps. As they walked, the barely moving air got progressively cooler.
Finally, Hobbes led them down a last flight of steps, and they emerged into a long open area split lengthways into two levels with each end disappearing off into large tunnels.
Hobbes brought them to a halt.
"This is the place where the trains would stop for passengers." He nodded to the tunnel mouth nearest where they had come in.
"The train would come from that direction," he turned to face the other way and pointed. "And it would leave that way. That's the way we have to go now."
Bodil pulled her jacket tighter. The draught coming from the tunnel was really quite chilly now, especially after the warm, humid air of the higher levels.
"So, what's down there Mister Hobbes?"
The party followed as Hobbes set off towards the tunnel mouth.
"Another station. One not on the old maps."
Weis trotted on ahead, looking around all the time for bugs to either shoot at or stomp on. Professor Hill caught up with Hobbes.
"What do you mean? Why would a station not be on the map?"
Ellie fell in behind the pair of archaeologists, listening.
"Because they went and built the station we just came from. That one was a junction of the Northern and Central lines." He nodded towards the approaching tunnel.
"The one down there became superfluous, so it was abandoned. That was over a hundred years before The Fall by the way.
Even in the last days, people who travelled this line never knew about the abandoned station. By then it had already been lost from living memory."
Just before they entered the tunnel, Ellie tugged on the archaeologist's sleeve, bringing him and everyone to a halt.
"So why did they dig down to the station we came in at? Why didn't they dig straight down to the abandoned one?"
"Because they didn't know where to dig. We still don't. The station was called 'British Museum' station, but when we excavated the museum, there was no sign of any station there.
We have no idea where the entrance might be."
They entered the tunnel.
The further they progressed, the more archaeology appeared and in steadily better condition. The steel rails they followed were rusted but still held their shape.
Cables, too, though their supports had rusted away and allowed them to fall to the ground,
still snaked along the tunnel floor mostly intact thanks to the thick insulation protecting them through the centuries.
Bodil and Ellie walked together. Although Pre-Fall history was not her field, the professor explained as much as she could remember of ancient underground mass transit systems.
When Ellie asked about what she thought were pipes Bodil corrected her and explained how the existing tunnels were often used by power companies as conduits for
the high-power electrical cables that were more usually strung from enormously high steel pylons.
When they walked through a particularly nasty-smelling section of the tunnel, she was also able to explain that sewerage companies sometimes did the same thing.
It made a change for Bodil to be able to enthuse about history with Ellie. Up until now, Ellie had always seemed to her to be disinterested or even disdainful about the past.
To actually have her asking questions was warmingly pleasant.
Eventually, though, she found herself more and more having to refer Ellie to Mister Hobbes for answers to her increasingly specific questions.
Up ahead, Hobbes and Weis had come to a halt and seemed to be waiting for them.
When Bodil, Ellie and Gregor arrived, it was to stand on a wide ramp and look up into a large, dark hole that had been created in the side of the tunnel.
The edges of the hole had been tidied up and reinforced.
"Ladies and gentlemen." Hobbes intoned with false ceremony. "May I present, 'British Museum Station." With that, he and Weis swung around and shone their torches directly through the hole.