http://www.amazon.com/dp/B007CJKK84 and tells how the Undead Spirits move.
Here is a short sample:-
The Sergeant sat up in the saddle, the hills around the troop were quiet which was unsettling as he knew the Comanche would be near, but the air was quiet, too quiet, "Well, here we are Cap'n. Those cliffs are where they are s'posed to be hiding out. I don't like it, sir, the Comanche's should have chased us, but they gave in too easy for my liking."
Captain March of the 17th US Cavalry took a few moments to observe what was going on around the soldiers, then he said, "I know, I feel the same about this, Sergeant; Corporal Hind, you know what to do, son."
"Yes sir. If you and the men don't show at the cave mouth in twenty minutes, I'm to ride back to the wire station and ask the fort to send out Pete Jackson and Mike Horner and get them to close the caves off with explosives."
March took the glasses from the Sergeant and studied the caves at the top of the cliff face, "Too far from the top to climb down and as far as I see, we have only a tiny ledge to walk on when we get there."
The Sergeant rubbed the stubble on his chin and said "You ain't thinking of coming back are you, sir."
March turned to him and said, "It did cross my mind, Sergeant; I want to get out as much as anybody, but our objective is clear."
"Yes, sir, I read despatches too. Close the caves off!"