Brayan's Gold (The Demon Cycle, #1.5)

Arlen Bales 17, apprentice Messenger in brand new armor, is ready for the first time beside a trained Messenger on a simple overnight trip. Instead Arlen finds himself alone on a frozen mountainside, carrying a dangerous cargo to Count Brayan’s gold mine, one of the furthest points in the duchy. And One Arm, giant rock demon, hunts him still. Novella.