The aerial lens’s burn had been about equally deep everywhere, so when it had blazed across Gale Crater it had cut a wide swath through the rim on the northeast and southwest sides; but these cuts were higher than the canal bed elsewhere, so that narrower cuts had been excavated through them, and locks installed, and the inner crater made into a high lake, a bulb in the canal’s endless thermometer. The Lowellian system of ancient nomenclature was in abeyance here for some reason, and the northeastern locks were bracketed by a little divided town called Birch’s Trenches, while the southwestern locks’ larger town was called Banks. The town Banks covered the meltzone of the burn, and then rose in broad bending terraces onto the unmelted rim of Gale, overlooking the interior lake. It was a wild town, crews and passengers of passing ships pounding down their gangplanks to join a more or less continuous festival. On this night the party was focused on the arrival of the Free Mars campaign. A big grassy plaza, perched on a wide bench over the lake lock, was jammed with people, some attending to the speeches given from a flat rooftop stage overlooking the plaza, others ignoring the commotion and shopping, or promenading, or drinking, or sitting over the lock eating food purchased from small smoky stands, or dancing, or wandering off to explore the upper reaches of the town.