“It was a close call,” laughed the other.  “He’s got to give us a dinner for helping him out of this.”

“We’d have caught him red-handed,” said Crosby, “if we’d been five minutes sooner.  Lord!” he gasped.  “It makes me cold to think of it.  The men would have shot him off his horse.  But what a story for those women!  I hope I’ll be there when they tell it.  If Ranson can keep his face straight, he’s a wonder.”  For some moments they raced silently neck by neck, and then Curtis again leaned from his saddle.  “I hope he has turned back to the post,” he said.  “Look at the men how they’re keeping watch for him.  They’re scouts, all of them.”

“What if they are?” returned Crosby, easily.  “Ranson’s in uniform—­ out for a moonlight canter.  You can bet a million dollars he didn’t wear his red mask long after he heard us coming.”

“I suppose he’ll think we’ve followed to spoil his fun.  You know you said we would.”

“Yes, he was going to shoot us,” laughed Crosby.  “I wonder why he packs a gun.  It’s a silly thing to do.”

The officers fell apart again, and there was silence over the prairie, save for the creaking of leather and the beat of the hoofs.  And then, faint and far away, there came the quick crack of a revolver, another, and then a fusillade.  “My God!” gasped Crosby.  He threw himself forwards digging his spurs into his horse, and rode as though he were trying to escape from his own men.

No one issued an order, no one looked a question; each, officer and enlisted man, bowed his head and raced to be the first.

The trail was barricaded by two struggling horses and an overturned buckboard.  The rigid figure of a man lay flat upon his back staring at the moon, another white-haired figure staggered forward from a rock.  “Who goes there?” it demanded.

“United States troops.  Is that you, Colonel Patten?”

“Yes.”

Colonel Patten’s right arm was swinging limply at his side.  With his left hand he clasped his right shoulder.  The blood, black in the moonlight, was oozing between his fingers.

“We were held up,” he said.  “He shot the driver and the horses.  I fired at him, but he broke my arm.  He shot the gun out of my hand.  When he reached for the satchel I tried to beat him off with my left arm, but he threw me into the road.  He went that way—­toward Kiowa.”

Sergeant Clancey, who was kneeling by the figure in the trail, raised his hand in salute.  “Pop Henderson, lieutenant,” he said.  “He’s shot through the heart.  He’s dead.”

“He took the money, ten thousand dollars,” cried Colonel Patten.  “He wore a red mask and a rubber poncho.  And I saw that he had no stirrups in his stirrup-straps.”

Crosby dodged, as though someone had thrown a knife, and then raised his hand stiffly and heavily.

“Lieutenant Curtis, you will remain here with Colonel Patten,” he ordered.  His voice was without emotion.  It fell flat and dead.  “Deploy as skirmishers,” he commanded.  “G Troop to the fight of the trail, H Troop to the left.  Stop anyone you see—­anyone.  If he tries to escape, cry ‘Halt!’ twice and then fire—­to kill.  Forward!  Gallop!  March!  Toward the post.”