Nirgal walked out of the building, through the city to his room. He packed his little collection of clothes and toiletries, and took the subway out to the launching pad, and asked Monica for the use of one of the single-person blimpgliders. He was ready for soloing, he had put in enough hours in simulators and with teachers. There was another flight school down in Marineris, on Candor Mensa. He talked to the school officials on the launchpad; they were willing to let him take the blimpglider down there, and have it returned by another flier later.

It was midday. The Tharsis downslope winds had started, and would only get stronger as the afternoon progressed. Nirgal suited up, got into the pilot’s seat. The little blimpglider slid up the launching mast, held by the nose; and was let free.

He rose over Noctis Labyrinthus, turned east. He flew east over the maze of interlocking canyons. A land split open by stress from below. Flight out of the labyrinth. An Icarus who had flown too close to the sun, gotten burned, survived the fall— and now flew again, this time down, down, down, ever down. Taking advantage of a hard tailwind. Riding a gale, shooting down over the shattered dirty ice field that marked Compton Chaos, where the great channel outbreak had begun in 2061. That immense flood had run down Ius Chasma; but Nirgal angled north, away from the glacier’s flow, and then flew east again, down into the head of Tithonium Chasma, which paralleled Ius Chasma just to the north.

Tithonium was one of the deepest and narrowest of the Marineris canyons— four kilometers deep, ten wide. He could fly well below the level of the plateau rims and still be thousands of meters over the canyon floor. Tithonium was higher than Ius, wilder, untouched by human hands, seldom traveled in, because it was a dead end to the east, where it narrowed and became rough-floored as it got shallower, then abruptly stopped. Nirgal spotted the road that switchbacked up the eastern head wall, a road he had traveled a few times in his youth, when all the planet had been his home.

The afternoon sun dipped behind him. The shadows on the land lengthened. The wind continued to blow strong, thrumming over the blimpglider, whining and whooshing and keening. It blew him over the caprock of the rim plateau again, as Tithonium became a string of oval depressions, pocking the plateau one after the next: the Tithonia Catena, each dip a giant bowl-shaped depression in the land.