''I am sending the nanos to scout the other sides of this U,'' Nelly said.
''Maybe we need to look at the paving,'' Beni said. ''Maybe they liked to walk downhill into a place.''
''We didn't see any basements in the buildings that are open,'' Abby pointed out.
Kris let the chatter wash over her, something she'd react to if and when she needed to. The building itself was having its own effect on her. It towered, but it also leaned back, away from her, hiding its upper limits from her eye. What impact had the original architect sought on his public. No columns here. No towering straight walls.
Totally alien.
''Kris, we seem to have found a break in the wall that is linear,'' Nelly reported.
Kris led an avalanche of ''Where?''
''I will try to have the nanos mark the separation. It hardly qualifies as a crack. The nanos cannot penetrate it.''
''That really is small!'' Kris said. It took several tries to mark the outline of the potential door. The first two efforts at marking it resulted in slight puffs of dye marker drifting away on the tiny updrafts rising in the heat of the building.
The third try succeeded in leaving a thin yellow mark. Slowly a pattern formed. It started about five meters away at the bottom where the building met the pavement. Then it rose in an arch, widening. ''They were round centipedes,'' Kris said.
The circling pattern met at the top. No flourishes, nothing that Mother called gingerbread. Just a circle cut off at the bottom by the flat line of the pavement.
''I guess that qualifies as a door,'' Jack said.
''Only if we can open it,'' Kris reminded them. ''Nelly, have your nanos look for something like a keypad or door lock. Anything that might open it.''
''I have had them scouring the wall around it, as well as the wall across from it. Kris, what you see is all that we have found. This is a very blank wall.''
''Thank you, Nelly,'' Kris said. Nelly's nonexistent feathers seemed to be a bit ruffled. Maybe some human respect would soothe. ''Beni, do you have any signal that we might use for an ‘open sesame'?''
''All I'm getting is the usual noise I've been hearing. Static with too much of a hint at some organization.''
''Anyone want to try explosives?'' Abby said.
''You really think anything we've got will mar something that's withstood a million years?'' Jack said.
''Nothing beats a try but a failure,'' the maid answered.
''Let's start with the lasers,'' Kris ordered. The lasers had been very low-powered to cut brush. Now the sailors dialed one up and applied it to a section of wall.
To no noticeable effect.
''Kris, feel that?'' Nelly said a full minute later.
''It ought to be white hot.''
''Yes, but my nanos report that it is no warmer than the surrounding wall.''
''Where's the heat going?'' the sailor with the laser said, putting it down.
Kris reached slowly for the place he'd been working on. No heat came back at her. She touched it. Her gauntleted hands transmitted no warmth. ''Whatever this stuff is, I want it on the hide of my next ship.'' Murmurs of agreement filled the net.
''Kris, I may have spotted something in the static,'' Nelly said, interrupting them all standing around looking dumb.
''What do you think you have?''
''Among the signals I found on the stone chip I have been analyzing are a whole series of sequences that seem to make no sense at all. They are just in this one place on the chip with no reference to anything.''
''And,'' Kris said.
''One of the sequences coming from the spire is the first half of one of those sequences from Santa Maria.''
''An entrance code?''
''Your guess is as good as mine,'' Nelly answered. Kris could almost hear a laugh run through the humans on net. Almost. Maybe they turned their mikes off.
''Well, let's see how good your guess is, Nelly. Play the sequence back,'' Kris said.
There was a pause. The door, if that was what it was, stayed closed. ''I just played it,'' Nelly said.
''Do we need to hunt for a different frequency to reply?'' Beni asked.
''That could put us here forever,'' Comm Boss at his elbow sighed, but he seemed to have intercepted Nelly's signal and was already working his own black box.
''Or maybe we didn't send it right?'' Abby said.
''Your thoughts,'' Kris said.
''Nelly, you sent it the whole sequence, right?''
''Yes.''
''But was it sending out the whole sequence, or just part of it?''
''It was sending only the first part.''
''Send only the second part,'' Kris said.
And in front of them, the entire door moved up and out of their way. ''Very, very good, Nelly,'' Kris said as the doorway reached full open.
Ahead of Kris spanned a large, empty space. The only light came from the open door. By it she saw the building's ribbed outer wall rising up. The floor inside had a series of designs laid into its speckled-green stone that formed no pattern Kris could comprehend. Nelly, you working on it?
I am storing it for later study, Kris, when I have more of it available.
Right. ''Are the nanos inside?''
''Yes, Kris. They report nothing dangerous. However, they do appear to be gaining weight. They are having to use extra fuel to stay aloft.''
''What's making them heavy?'' Jack asked.
''I do not know. I would have to bring them out to evaluate the problem fully.''
''Bring a couple out and let's have a look,'' Kris ordered.
A minute later, several nano-scouts were out. ''Ah, Kris, they are no longer overweight. I can find nothing on them,'' Nelly said, sounding rather puzzled for a computer.
''Interesting,'' Jack said. Kris could almost hear his eyebrows going up behind the mirror of his faceplate.
''So, a million years ago some clean freak designed gear to keep this place spotless. And they're still at it. Too bad we can't tell her how good she was.''
''Maybe so, but how will it effect our suits?'' Jack asked.
''I intend to find out,'' Kris said.
''I'm glad you got your itty bitty buddies out in front,'' Abby said, coming back from across the street twirling a stick as tall as she was. ''But I'm gonna trust something a bit more primitive to test out where I put my dainty feet.''
''I think I'll get a stick, too,'' Beni said, heading for the same small copes.
''Get me one, too,'' Kris said after him.
''Me three,'' Jack added.
''I'll get one for everyone going in,'' a sailor with a laser answered as he followed the chief.
''How many are going in?'' Jack asked.
''You, me, Abby, Beni. Doc, you willing to stay behind?''
''I really want to get a look inside. Take air samples. Why not leave our radio boss behind. He's got the antenna to net us to the Resolute. Him and one of the gunners.''
Since Abby was one of the two gunners, that left only one. After some good ribbing about bringing back lush native girls for Comm Boss, and a hunk for the gunner, that was settled.
Beni headed back with an armful of walking staffs. ''Bring me a big rock,'' Kris called. ''Something to put in the doorjamb.''
The laser wielder turned back, picked a large one that looked like it had started life as a cut slab, but been broken in half. Radio trotted over to give him a hand and the two of them lugged it in and set it upright along the right side of the door.
''Think that will stop it from closing?'' Jack asked, eyeing the half meter tall block.
''Long enough for us to get out,'' Kris said.
''Here we are, the finest example of twenty-fourth century womanhood,'' Abby said, ''and manhood, and we're reduced to using rocks for doorstops.''
''I'm sure the next expedition will be much better prepared,'' Kris said. ''Now, do you intend to fold this hand and leave all the fun to them, or are we going to take our own primitive step into, well, whatever.''
Abby put out her walking stick, tapped the stones on the inside of the doorsill, and stepped across. ''One small step for this woman, one big question mark for the rest of you.''