BOUNDARY(151)

Surprisingly, A.J. held out for natural causes. "We know there were aliens about so we tend to think everything weird is their doing. But I'm betting that Mars itself has got more weird saved up for us than Bemmie could have cooked up in the short time he was here. Maybe it's something left over from the era when Mars had lots of running water."



"Doubtful," Baird commented. "A lot of the rocks involved in water deposition are, themselves, fairly heavy with water content. They tend to disintegrate in this kind of atmosphere as they dehydrate. But you have basalt over the top of the area, so it's possible that you're looking at something caused by volcanic action eons ago."



The steep path, if that's what it was and not some kind of lava-flow or other natural channel, took considerable time and effort to climb. Finally, they stood at the top and looked down a tunnel about the same size as the last one. Helen eyed the ceiling suspiciously; there were signs of cracking at intervals along the way.



And then they rounded the corner and found the door.



The construction of the doorway was similar to those found in Phobos base, but clearly not identical. A.J. sent back high-resolution pictures in all spectra to Thoat. Inside the rover, Joe studied the doorway and other structures partially visible around the door before they disappeared into the rock at either side. He looked at them both in normal imagery and the more esoteric, partial imagery A.J.'s sensors could extract out of the stubbornly shielded material.



"It's not the same," he said finally, "but it looks like the same kind of technology was involved. That's the best way I can put it. It doesn't differ from the Phobos designs nearly as much as those do from ours. It's more like the difference between Egyptian and Greco-Roman architecture."



"So you think it's the same species, in other words." There was a note of disappointment in Madeline's voice.



"That'd be jumping to conclusions," Helen said. "I can think of other possibilities. To name one, this could have been built by a different species—including a hostile species—but one which had been in contact with the Bemmies long enough for their technological methods to have gotten largely shared. The way that, nowadays, an office building in Tokyo or New Delhi doesn't look that much different from one in New York or Barcelona. For that matter, if aliens had examined the Japanese planes that fought at the battle of Midway, they'd have had a hard time seeing much difference from the American ones."



"True," A.J. said, "provided the two species were physically similar enough. Even if we shared technology with Bemmie, there's still no way we'd design a lot of things the way they do. Or vice versa. That door's quite a bit taller than I'd expect a Bemmie door to be, for instance. Although it could've been a small cargo door, I suppose."



"How about getting it open?" Madeline asked.



"Brute-force it," Joe proposed. "You don't want to try anything involving arc-cutting in there."



"Why . . . oh."



"'Oh' is right, A.J. You want to find out what it's like to be on the inside of a giant neon light tube? At the least you'd probably fry your electronics, and at the worst you'd fry yourself. The pressure's slightly higher down there, but I don't know that it would make enough difference—and we sure don't want you to be the experimental guinea pigs. No way around it. You'll have to come back here and get some of the excavation equipment."



A.J. sighed. "Oh, now that's going to be fun. Even with the low gravity."



"Well, you could just come back and forget about it, and we all just sit around swapping jokes until the rescue shuttles get here in a couple months."



"I do not think so," Helen said firmly. "Okay, guys, let's head back. Tomorrow is going to be a big day."



Madeline's voice was resigned. "More like tomorrow and the day after, at least. I've done operations like this before—don't ask where or why—and I think you're underestimating the difficulty we're going to have getting that equipment down here."



Helen thought the security specialist was probably right. But she didn't really care. She was bound and determined to get into the base. If that meant dragging equipment deep into Martian caverns, well, it couldn't be that much worse than setting up a major dig.



She led the way, as they left, already working on the problem. "We'll need to set up a field camp and supply area for this operation. We don't want to have to travel all the way back to Thoat and main camp whenever we run short of a few items. The exotic location aside, this isn't fundamentally much different from any major dig. When you're out in the badlands, you don't hop in a vehicle and drive off every time someone's thirsty and wants a soda."