Having arrived at that conclusion, he had asked her to marry him, and upon the match-box had marked the date and the hour.  Since then she had given him many pretty presents, marked with her initials, marked with his crest, with strange cabalistic mottoes that meant nothing to any one save themselves.  But the wooden match-box was still the most valued of his possessions.

As he rode into the valley the rays of the moon fell fully upon him, and exposed him to the outpost as pitilessly as though he had been held in the circle of a search-light.

The bronzed Mausers pushed cautiously through the screen of vines.  There was a pause, and the rifle of the sergeant wavered.  When he spoke his tone was one of disappointment.

“He is a scout, riding alone,” he said.

“He is an officer,” returned the sharp-shooter, excitedly.  “The others follow.  We should fire now and give the signal.”

“He is no officer, he is a scout,” repeated the sergeant.  “They have sent him ahead to study the trail and to seek us.  He may be a league in advance.  If we shoot him, we only warn the others.”

Chesterton was within fifty yards.  After an excited and anxious search he had found the match-box in the wrong pocket.  The eyes of the sharp-shooter frowned along the barrel of his rifle.  With his chin pressed against the stock he whispered swiftly from the corner of his lips, “He is an officer!  I am aiming where the strap crosses his heart.  You aim at his belt.  We fire together.”

The heat of the tropic night and the strenuous gallop had covered El Capitan with a lather of sweat.  The reins upon his neck dripped with it.  The gauntlets with which Chesterton held them were wet.  As he raised the match-box it slipped from his fingers and fell noiselessly in the trail.  With an exclamation he dropped to the road and to his knees, and groping in the dust began an eager search.

The sergeant caught at the rifle of the sharp-shooter, and pressed it down.

“Look!” he whispered.  “He is a scout.  He is searching the trail for the tracks of our ponies.  If you fire they will hear it a league away.”

“But if he finds our trail and returns—­”

The sergeant shook his head.  “I let him pass forward,” he said grimly.  “He will never return.”

Chesterton pounced upon the half-buried match-box, and in a panic lest he might again lose it, thrust it inside his tunic.

“Little do you know, El Capitan,” he exclaimed breathlessly, as he scrambled back into the saddle and lifted the pony into a gallop, “what a narrow escape I had.  I almost lost it.”

Toward midnight they came to a wooden bridge swinging above a ravine in which a mountain stream, forty feet below, splashed over half-hidden rocks, and the stepping stones of the ford.  Even before the campaign began the bridge had outlived its usefulness, and the unwonted burden of artillery, and the vibrations of marching men had so shaken it that it swayed like a house of cards.  Threatened by its own weight, at the mercy of the first tropic storm, it hung a death trap for the one who first added to its burden.