Old Mars

He pulled out the trowel and scraped at the damp soil with its finely honed edge. When the top layer came up fairly easily, he decided to use the excavator, and Rekari helped him maneuver it out of the boat and roll it into place. He flipped the switch, and the small machine came to life and began to scuff at the surface and toss the soil aside. He ran it over the suspicious area, and at each pass, it dug deeper, a centimeter at a time.

Fifty centimeters below the surface, it exposed a polished stone surface. He jumped down into the shallow pit and went to work with trowel and brush to clean it off and find its edges.

Fully exposed, the smooth stone measured a little less than one meter by two, oriented with the longer side running almost precisely north and south. The western edge merged with rougher stone that extended toward the canal. The eastern edge ended sharply, and when he dug a narrow trench downward there, he found a smooth vertical face about fifteen centimeters in depth, with another horizontal surface at the bottom. He lengthened his trench eastward, found another edge after about forty centimeters, another vertical face, and another horizontal surface below that. It looked like the beginning of a stairway. He started the excavator again, set the depth control to maximum, and spent the rest of the afternoon clearing the three steps. Not long before sunset he had a hole two meters by three, almost a meter deep, and three steps that led … to what?

Rekari had been sitting at the edge of the hole for most of the excavation. Now Dave climbed up and sat beside him in the waning sunlight. “There has to be something down there,” he said. “Nobody builds stairs to nowhere.”

Rekari signed his agreement.

“If this were Earth, I’d say maybe a sunken amphitheater. There’s room for a pretty broad arc before you reach those boulders.” He gestured toward them.

“An interesting thought,” said Rekari.

“Maybe there’s a polygon of steps.” He looked left and right, measuring the area with his eyes. “That would be a major excavation. I’d have to ask for a grant from Syrtis University and a crew of grad students to help. It could be very exciting.”

“It’s only three steps,” said Rekari.

Dave signed agreement. “I’ll need more evidence before I can write that grant proposal.” He swiveled his legs out of the hole and stood up. “Well, more digging tomorrow.” He smiled at Rekari. “It begins to seem like Dad had a really good lead.”

Rekari looked down at the steps, now in deep shadow. “Your father taught me a great deal in the years of our partnership,” he said. “He might have wondered if the ground level was lower thousands of years ago, and if these steps might not have led upward from there to something that no longer exists.”

Dave crossed his arms over his chest and looked into the hole, too. “Well, that’s possible,” he said. “And a lot less exciting. But I have to find out. I could use some peanut butter now, and a good night’s sleep.”

The next day, he found more steps leading downward. And more. Periodically, he pulled the excavator back to the surface and lengthened the opening, two meters at a time, so that the forward wall would not collapse from being undercut. In the pit, the excavator was soon beyond its ability to loft soil the entire distance to the surface, and so he and Rekari alternated using the shovel to finish clearing away what the machine tossed to the higher steps. By midafternoon, the hole was more than five meters long, and there were ten steps leading down. By midafternoon two days later, it was ten meters long, with twenty steps.

That was when they hit the door.

It was an elliptical panel, vertical, about two meters tall and a meter and a third wide. As he brushed the packed soil away and examined it with his flash, Dave saw that it was set flush into a smooth stone wall, but the panel itself was made of metal, and he was amazed at its condition—the corrosion was minimal, as if the door had been left there a hundred years ago instead of thousands.

“Look at this,” he whispered, as if Rekari, standing behind him, needed to be told that something was there.

Rekari stretched out a hand and touched the door almost reverently.

There was no handle, no lock that might admit a key or a tool, no obvious way to open it. But it was wider than the step in front of it was deep, which meant it had to open away from the stairway. Dave set both of his hands against its right side and pushed tentatively, then with increasing effort. The door did not move. He tried the other side, with the same results. “I didn’t think I’d need to bring a crowbar,” he muttered. Holding the flash close, he peered at the metal, going over it centimeter by centimeter, but all he could find were two hairline joins, one the length of the vertical axis, the other at the horizontal, both too tight to admit even the sharp edge of his trowel.