The mountain ranges ringing the Hellas Basin were widest in the western crescent called the Hellespontus Montes, the range on Mars most reminiscent of Terran mountains. To the north, where the piste from Sabishii and Burroughs crossed into the basin, the range was narrower and lower, not so much a matter of mountainous terrain as of an uneven drop to the basin floor, the land seemingly shoved to the north in low concentric waves. The piste threaded its way down this hilly slope, and often it had to switch-back down long ramps cut into the sides of the rock waves, each new one lower than the last. The train slowed greatly for the turns, and for many minutes at a time Maya could look out her window either straight at the bare basalt of the wave they were descending, or out over a big expanse of northwest Hellas, still three thousand meters below them: a wide flat plain, ochre and olive and khaki in the foreground, then, out on the horizon, a dirty jumble of white, winking like a broken mirror. That was the glacier over Low Point, still mostly frozen, but thawing more each year, with melt ponds on its surface, and deeper pods of water far below— pods which teemed with life, and occasionally broke onto the surface of the ice, or even the adjacent land— for this lobe of ice was growing fast. They were pumping water out of aquifers below the surrounding mountains onto the basin floor. The deep depression in the northwest part of the basin, where Low Point and the mohole had been, was the center of this new sea, which was over a thousand kilometers long, and at its widest, over Low Point, three hundred kilometers across. And situated in the lowest point on Mars. A situation rich with promise, as Maya had been maintaining from the very moment they had landed.

The town Odessa had been established well up the north slope of the basin, at the—1-kilometer elevation, where they planned to stabilize the final level of the sea. Thus it was a harbor town waiting for water, and with that in mind the southern edge of the town was a long boardwalk or corniche, a wide grassy esplanade that ran inside the tent, which was secured in the edge of a tall seawall that now stood above bare land. The view of the seawall as the train approached gave one the impression that it was a half-town, with a southern part that had been split off and disappeared.