Divorced from the sunlight, the city operates on a full-day schedule, the unwavering light of the glowing orbs keeping the city active at all hours. The orbs are quite large, and hang a couple hundred feet in the air; attacking them might be difficult. Fortunately, the guard patrols, while frequent, seem to stick to fairly set routes, deliberately avoiding the 'bad' parts of the city. Unfortunately, the vault is located far from those 'bad' portions, and is heavily, and regularly patrolled, including at least one detachment in the plaza just outside the vault, protecting it, and other, nearby buildings.