Every guard worth his salt in Canterlot knows the rules of patrolling the Mountainside District: You don't patrol the district alone. You don't patrol it alone, especially at night. But if you do patrol it, you expect trouble. But if you can help it, you don't patrol it at all.
But when her platoon is short on ponies, Private Sword Glitter gets assigned to patrol the Mountainside District. Alone. At night.
Features the main character from my previous Royal Guard story, A Hearth's Warming Patrol, but can be read independently without issues.