Nocturne: a hymn for the evening, to accompany the setting of the sun and herald the coming of darkness.

Ancient secrets, mysterious artifacts, and the ambitions of ponies over the course of centuries collide as the peace and harmony Equestria has enjoyed for a millennium is threatened--not least of all by none other than Twilight Sparkle!

Night is falling, and a storm lingers on the horizon. When the sun rises again, what will remain?