percy darrow, with the keenness that always characterised his mental apprehension, had understood enough of my strangled cry. he had not hesitated nor delayed for an explanation, but had turned track and was now running as fast as his long legs would carry him back toward the opening of the ravine. my companions stood watching him, but making no attempt either to shoot or to follow. for a moment i could not understand this, then remembered the disappearance of perdosa. my heart jumped wildly, for the mexican had been gone quite long enough to have cut off the assistant's escape. i could not doubt that he would pick off his man at close range as soon as the fugitive should have reached the entrance to the arroyo.

there can be no question that he would have done so had not his mexican impatience betrayed him. he shot too soon. percy darrow stopped in his tracks. although we heard the bullet sing by us, for an instant we thought he was hit. then perdosa fired a second time, again without result. darrow turned sharp to the left and began desperately to scale the steep cliffs.

i once took part in a wild boar hunt on the coast of california. our dogs had penned a small band at the head of a narrow _barranca_, from which a single steep trail led over the hill. we, perched on another hill some three or four hundred yards away, shot at the animals as they toiled up the trail. the range was long, but we had time, for the severity of the climb forced the boars to a foot pace.

it was exactly like that. percy darrow had two hundred feet of ascent to make. he could go just so fast; must consume just so much time in his snail-like progress up the face of the hill. during that time he furnished an excellent target, and the loose sandstone showed where each shot struck.

a significant indication was that the men did not take the trouble to get nearer, for which manoeuvre they would have had time in plenty, but distributed themselves leisurely for a shooting match.

"first shot," claimed handy solomon, and without delay fired off-hand. a puff of dust showed to the right. "nerve no good," he commented, "jerked her just as i pulled."

pulz fired from the knee. the dust this time puffed below.

"thought she'd carry up at that distance," he muttered.

the nigger, too, missed, and thrackles grinned triumphantly.

"i get a show," said he. he spread his massive legs apart, drew a deep breath, and raised his weapon. it lay in his grasp steady as a log, and i saw that percy darrow's fate was in the hands of that dangerous class of natural marksman that possesses no nerves. but for the second time my teeth saved his life. the trigger guard slipped against thrackles's lacerated hand almost at the instant of discharge. he missed; and the bullet went wide.

darrow had climbed a matter of twenty feet.

now the seamen distributed themselves for more leisurely and accurate marksmanship. handy solomon lay flat on his stomach, resting the rifle muzzle across the top of a sand dune. pulz sat down, an elbow on either knee for the greater steadiness. the nigger knelt; but thrackles remained on his feet. no rest could be steadier than the stone-like rigidity of his thick arms.

the firing now became miscellaneous. no one paid any attention to anyone else. each discovered what i could have told them, that even the human figure at five hundred yards is a small mark for a strange rifle. the constant correction of elevation, however, brought the puffs of dust always closer, and i could not but realise that the doctrine of chances must bring home some of the bullets. i soon discovered by way of comfort that only thrackles and handy solomon really understood firearms; and of those two thrackles alone had had much experience at long range. he told me afterward he had hunted otter.

about halfway up the cliff thrackles fired his fifth shot. no dust followed the discharge; and i saw percy darrow stagger and almost lose his hold. the men yelled savagely, but the assistant pulled himself together and continued his crawling.

the sun had been shining in our faces. i could imagine its blurring effect on the sights. now abruptly it was blotted out, and a semi-twilight fell. we all looked up, in spite of ourselves. an opaque veil had been drawn quite across the heavens, through which we could not make out even the shape of the sun. it was like a thunder cloud except that its under surface instead of being the usual grey-black was a deep earth-brown. as we looked up, a deep bellow stirred the air, which had fallen quite still, long forks of lightning shot horizontally from the direction of the island's interior, and flashes of dull red were reflected from the canopy of cloud.

the men stared with their mouths open. undoubtedly the change had been some time in preparation, but all had been so absorbed in the affair of the doctor's assistant that no one had noticed. it came to our consciousness with the suddenness of a theatrical change. a dull roaring commenced, grew in volume, and then a great explosion shook the very ground under our feet.

we stared at each other, our faces whitening.

"what kind of hell has broke loose?" muttered pulz.

the nigger fell flat on his face, uttering deep lamentations.

"voodoo! voodoo!" he groaned.

a gentle shower of white flakes began, powdering the surface of everything. far out to sea we could make out the sun on the water. gradually the roaring died down; the lightning ceased. comparative peace ensued. we looked again toward the cliff. percy darrow had not for one instant ceased to climb. he was just topping the edge of the bluff. handy solomon, with a cry of rage, seized another rifle and emptied the magazine at him as fast as the lever could be worked. the dust flew wild in a half dozen places. darrow drew himself up to the sky line, raised his hat ironically, and disappeared.

"damn his soul!" cried handy solomon, his face livid. he threw his rifle to the beach and danced on it in an ecstasy of rage.

"what do we care," growled thrackles, "he's no good to us. w'at i want to know is, wat's up here, anyhow!"

"didn't you never see a volcano go off, you swab?" snapped handy solomon.

"easy with your names, mate. no, i never did. we better get out."

"without the chest?"

"s'pose we go up the gulch and get it, then," suggested thrackles.

but at this handy solomon drew back in evident terror.

"up that hole of hell?" he objected. "not i. you an' pulz go."

they wrangled over it, pulz joining. perdosa, shaken to the soul, crept in, and made a bee-line for the rum barrel. he and the nigger were frankly scared. they had the nervous jumps at every little noise or unexpected movement; and even the natural explanation of these phenomena gave them very little reassurance. i knew that darrow would hurry as fast as he could back to the valley by way of the upper hills; i knew that he had there several sporting rifles; and i hoped greatly that he and dr. schermerhorn might accomplish something before the men had recovered their wits to the point of foreseeing his probable attack. the uncanny cloud in the heavens, the weird half-light, and the explosions, which now grew more frequent, had their strong effect in spite of explanation. the men were not really afraid to venture in quest of the supposed treasure; but they were in a frame of mind that dreaded the first plunge. and time was going by.

but the fates were against us, as always in this ill-starred voyage. i, watching from my sand dune, saw a second figure emerge from the arroyo's mouth. it appeared to stagger as though hurt; and every eight or ten paces it stopped and rested in a bent-over position. the murky light was too dim for me to make out details; but after a moment a rift in the veil enabled me to identify dr. schermerhorn carrying, with great difficulty, the chest.