As the dark of night fell over the port of canterlot a lone ship stood in the harbor. Its silver flag floating on the wind as a young guard patrolled its corridors in search of any unwanted guests. It seemed to be normal for the capital of Equestria, home of the princess of day and the prince of night. All slept save those who worked the clubs or in the castle.
The castle seemed to hold an air of impenetrability, looming and foreboding in the early hours of the night. The night guard patrolled it watching, waiting, unseen and unheard. Had one of the chef's or maids traveled the corridor they would have not seen nor even known that nocturne’s personal guard was there in the shadows each had been personally selected from the dwindling population of terrestrial’s by the guard captain herself.
As the time drew near for nocturne to begin the moons decent a lone stallion seemed to trot from the shadows themselves. He saw his goal, an ornate door with a custom mana lock. Sadly one fatal flaw was left exposed with the 'impenetrable' door: so long as one hinge was attached it could support the weight of whole door, a simple yet over looked error in the vaults design.
As the thief silently walked to the door a small vial slipped from under his tattered wings. When he was at the door he uncorked the vial and poured its contents upon the right side hinges of the vault door.
"Finally, my collection is complete. Now, on to the greatest treasure ever, the one piece." he said with a grin that only a master of shadows could do.
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The following day the night guard informed the princess and prince of their findings at the vault. How no bodies nor any evidence aside from a hoof drawn note was found at the scene.
Nocturne turned towards his sister and said "I think it’s time we let her off from her parole, with full near full pardon. You and I both know we need her and her crew to find this 'Silver' to bring back the elements."
As celesta raised the sun she agreed wholeheartedly, she called upon her page and said to tell captain nightfall she was free to roam the sea, under the ruling that she complete one final mission for the crown.