“The dome has no entrance as such. It was a perfect sealed sphere until it was cracked open like an eggshell. We think what did it was some kind of directed orbital gamma ray strike, about two thousand years ago.”
Rita looked around, awed by the age of the site. The floor inside the dome was flat, unnaturally smooth where the excavations had swept aside nearly two millennia of dirt and muck that had blown in or grown in.
“It’s concrete,” Julie explained, “but reinforced with graphene fibers. And there are embedded semiconductor chips all through the top few millimeters—synthetic sapphire substrate, powered by ambient light and microwave radiation. And I mean all through it—if you scraped up a cubic yard of the top layer, it’d contain more processing power than Google’s biggest data center. They don’t work anymore, though. Burned out centuries ago. They’re just junk, electronic waste.”
“What were they for?” Rita asked.
“We don’t know. The usual ubiquitous computing stuff, maybe: looking for and fixing cracks, monitoring the micro-environment, fly’s-eye optical sensors on the surface-dwelling chips, sniffing the ambient microbiological genome for biowar threats. Who knows? Radiation damage killed them after the dome breach. Ion migration over the centuries since then has blurred the surface features so badly that the geek squad can’t reverse-engineer them. It’s pretty cool stuff, but nothing we won’t be able to do ourselves within the next decade or two—if anyone wants to pour concrete that costs a million dollars a cubic yard. But that’s just one of the puzzles.”
They walked across the floor of the dome toward a cluster of white-walled buildings. Steel scaffolding surrounded them, stabilizing and providing ladders to the upper-story openings. “We think this was a barracks,” Julie continued. “There were external catwalks but they’d collapsed. Damaged in the attack, again. We think maybe they were fire escapes, if anyone made fire escapes out of 3-D-printed titanium alloy.”
“This was a military base, wasn’t it?” Rita asked.
“Probably, yes, and it’d explain the exotic metals: mil-spec suppliers seem to be a universal constant. But there’s other weird stuff you need to see. This is building 102. C’mon upstairs?”
Rita followed Julie up the aluminum stepladder that the DHS archaeologists had used to replace the fallen fire escapes. They entered on the first floor. “Where’s the light coming from?”
“The ceiling is wall-to-wall pixels, and while the display driver died centuries ago the backlight still works just fine. Although it took the PaleoComp people a couple of years to figure out how to power it.”
Rita looked around the structure. It was a room: as rectilinear and vacant as any other she’d seen. Which should, she felt, be a sign of something. The walls were lined with rows of what looked like bunk beds, layered three high. Yellowing polymers had crumbled away to reveal metal frames within. They had individual shutters to block out the light, high-density kit lockers between the head-end of one unit and the feet of the next. “It looks … efficient.”
“We think it was refuge accommodation. You’d see the same in any nuclear emergency bunker today.” Julie gestured around. “Tell me what you don’t see.”
“There are—” Rita blinked. “Where’s the bathroom? Where are the doors?” Suddenly the room made no sense at all. “You’re telling me they had to go out on the fire escape and downstairs and into another building to use the restroom?”
“It’s worse than that.” Julie gestured at the door they’d entered through. “That was an emergency exit, not an entrance. The ground floor is full to ceiling height with what seems to be a filtered HVAC system, bottled air for a day or so, and water tanks.”
“But how did they go to the bathroom?”
“Imagine they were world-walkers. How do you think they went to the bathroom?”
Rita stared at Julie for a few seconds. “The bathroom is in another time line?”
Julie nodded. “Very good: that’s what George—he’s our site director—thinks.” She turned slowly round, taking in the entire room. “They built a para-time fortress because they were being hunted by a para-time-capable adversary. We think it consists of several installations scattered across identical geographical locations in several time lines. They’d use some of the installations for offensive operations, others as logistics depots or hospitals and other rear-echelon facilities. All in the equivalent location, but in different time lines. Without having a knotspace map of the facility, the enemy couldn’t roll them all up. This one was the air raid shelter—passive, no emissions, hidden as well as they could. The entire outer shell of the dome is riddled with smart dust. We think it was stealthed to the point of optical and infrared invisibility, using the ground underneath it as a heat sink. If they came under attack, they could just jaunt in here for a few hours or until they could find an evac route. Eat ration packs and shit in a paper bag until it was time to leave.”
“Wow.” Rita looked around. “It’s the bomb shelter under—inside—a five-dimensional Army base? What killed them?”
“Our best theory is it took a gamma ray laser. Fired from low orbit, pumped by a megaton-range hydrogen bomb. But c’mon, let me show you the Gate. It’ll top anything you’ve seen so far.” Julie waved her toward the escape hatch/doorway and the ladder beyond.
Rita followed her, duck-walking laboriously in her protective suit. World-walkers with death rays and H-bombs. A hollow sense of dread gnawed at her sternum. What could top that?
CAMP SINGULARITY, TIME LINE FOUR, JULY 2020
On the other side of the cinder-block wall that bisected the floor of the dome, there was another dome. It was a dome within a dome, Rita noted, but this one lacked the strangely smooth curves and textures of the forerunner ruins. A bunch of modular buildings nuzzled up around its rim. Beyond them the excavation area on the dome floor took on a chaotic, jumbled geometry, as if the forerunner installation had been badly damaged there. “That’s where the mach wave converged,” Julie explained. “When the forerunners’ adversary cracked the outer dome the radiation pulse created a shock wave of superheated air. It expanded, hit the inside of the dome, and rebounded, focusing on this area. If you were standing anywhere else on the apron when it hit, you’d have been fried and blasted: but at the focal point you’d have been crushed instead, just by the overpressure.”
Rita shuffled along behind her in mild shock, her thoughts whirling. “What’s in the, the small dome?”
“That’s ours: we built it. Follow me and I’ll show you.” Julie led her along a reverberating metal catwalk that spanned a ten-meter-wide excavation site. The arachnoid shapes of archaeology robots crawled back and forth below their feet, ablating and recording everything as they drilled slowly down through the wreckage. “This is where I work most of the time,” Julie added brightly. “It’s an archaeologist’s dream job.”