Knight of Coins: Valguard Series, Book 1 by David N. Humphrey

A woman kidnapped by bandits. A mercenary sent alone to rescue her. Time is running out, the odds are against him and he must play a dangerous game to survive... High up in the fells, a mercenary called Valguard pits himself against a band of vicious thieves and seemingly impossible odds on a daring night-time raid on a remote, fortified stronghold to rescue a hostage. Meanwhile, his employer, The Duke, waits at the border for news of the mission. Will he outwit the ruthless group of over twenty bandits known as The Cutters? Or has his luck ran out and this time he has sent his friend to a very bloody death? The first Valguard book and prologue to the forthcoming novel 'Ten of Swords'