They worked as quickly as they could. The oncoming evening darkness forced them to light a few gas lamps in the library, but otherwise they relied on as little illumination as possible. As far as anypony outside knew, the extruded crystalline tower was deserted, all its inhabitants having decamped to Canterlot for the aborted Friendship Festival. None of the trio wanted lit-up windows to betray any hint otherwise and thereby attract undesired attention, either from the growing panic in the neighboring town or from the enemy airships beginning to peel off from their orbits over the vanquished city.