Boots and Saddles (The Pony Soldiers Book #7)

Clever and more cunning than any redskin, stronger and meaner than any white man, Colonel Colt Harding was called in to clean up Fort Wallace, Kansas, where a secret brotherhood of officers was torturing and killing soldiers who didn't cotton to their poisoned politics. The colonel had to move fast because bloodthirsty tribes of Sioux and Cheyenne were surrounding the fort on nearby Breecher's Island, and only Harding and his Lightning Troop could stop them. Remorseless men who lived to kill, Harding's misfits sneered in the face of danger, for no one had yet survived an all-out attack by the Pony Soldiers.