a hand, kicked a foot out of his left stirrup, and in a second Jack was swung up behind him and they were off.
"I hope to goodness we strike no more gopher holes," thought the boy, as they raced along, scarcely more slowly than when the plucky little calico had only a single burden to carry. Never had the brave little beast been used more unmercifully. Bud Wilson plied his heavy quirt on the pony's flanks as if he meant to lay the flesh open. To every lash of the rawhide the calico responded bravely, leaping forward convulsively.
"We'll beat him to it!" cried Jack triumphantly, as both riders fairly fell off the spent calico's back at the sluice gates.
"Yep, maybe; but we've got to get 'em closed first!" was Bud's laconic response.
Paying no further attention to the calico – which was too spent, anyhow, to attempt to get away – the two, the man and the boy, ran at top speed across the narrow wooden runway which led to the big wheels by which the gateways of the sluice were raised and lowered.
"If Ralph can only hold out!" gasped Jack, who, far up the stream had espied a small black object coming rapidly toward him, which he knew must be the head of his chum. Ralph was swimming easily, taking care not to wind himself, and looking out for any opportunity which might present itself to reach the bank. No sooner did he attempt to cross the current, however, than the water broke over him as if he had been a broached-to canoe. He confined his efforts, therefore, to keeping his head above water. Of the deadly peril that lay ahead of him he had, of course, no knowledge.
"Hurry, Bud!" cried Jack, in an agony of fear that they would be too late.
"All right now, take it easy, Jack. No use hurrying over this job," replied Bud easily, though his drawn face and the sweat on his forehead showed the agitation under which he was laboring.
"Consarn this thing! How's it work!" he muttered angrily, fiddling with the machinery, which was complicated and fitted with elaborate gears and levers to enable the terrific pressure of the water to be handled more easily.
Beneath their feet the stream – a mad torrent above – developed into a screaming, furious flood at the sluiceway. It shot through the narrow confines at tremendous velocity, shaking and tearing at the masonry buttresses as if it would rip them away.
To Jack's excited imagination, it seemed as if the swollen canal was instinct with life and malevolence, and determined to have human life or property in revenge for its confinement.
Suddenly the boy's eyes fell on something he had not noticed before. Beyond the floodgate the engineers of the irrigation canal, finding that the confinement of the water at the sluiceway tended to make the current too savage for mere sandy walls to hold it, had constructed a tunnel. This expedient had been resorted to only after numerous experimental cement retaining walls had been swept away.
Just beyond the buttresses on the other side of the sluice, the entrance of the tunnel yawned blackly. Like a great mouth it swallowed the raging flood as it swept through the sluice.
"Bud! Bud! Look!" cried Jack, pointing.
"Great jumping side-winders! I forgot the tunnel!" groaned Bud, his usually emotionless face working in his agitation. He had been handling the sluice desperately, but without result.
"We must close the gates within a second, or it will be too late!" shouted Jack, above the roar of the water. Ralph's despairing face was very close now.
"My poor kid, we can't!" wailed Bud.
"Why not?"
"The double-doggoned, dash beblinkered fool as looks after 'em has padlocked 'em, and we can't git 'em closed without a key!"
There was not a second to think.
Even as the discovery that it would be impossible to close the gates was made, Ralph's white face flashed into view almost beneath them.
Bud made a quick snatch at Jack's lariat, which the boy still retained, and snaked it down over the racing water.
"Missed!" he groaned, as Ralph's upturned face was hurried by.
At the same instant there came a splash that the cow puncher heard even above the roar of the water as it tore through its confines.
Bud glanced quickly round.
Where Jack Merrill had stood a moment before were a pair of shoes, the boy's coat and his shirt.
But Jack had gone – he had jumped to Ralph's rescue. As Bud, with a sharp exclamation of dismay, switched sharply round, he was just in time to see the forms of the two boys swallowed in the darkness of the irrigation tunnel.
CHAPTER IV.
THROUGH THE GREAT DARKNESS
Little given to emotion as he was, Bud Wilson reeled backward as if about to fall, and gripped the woodwork of the sluice till the blood came beneath his nails. His eyes were still riveted on the yawning black mouth of the tunnel, and the white-flecked, yellow water racing into it, when the followers of the chase for life came galloping up, leading the ponies of the two boys who had vanished. Blank looks were exchanged as they learned what had happened.
"Not a chance for them." was the consensus of opinion.
Jack Merrill was not a boy who does things without due thought, however. When he had jumped into what seemed certain death he had done so with a definite plan in his head.
In moments of intense mental strain the mind sometimes acts with lightning-like rapidity, and Jack had reasoned like a flash that the irrigation tunnel, being built to convey water to the lands of the Maguez Land and Development Company, probably emerged on their lands, which lay not more than a mile away. Of course, he was not certain of this, but the life of his friend was at stake.
Spent as his chum was, Jack thought Ralph could hardly last throughout the passage of the tunnel, while he, Jack, was fresh, and also a stronger swimmer. These thoughts had all raced through his mind while he kicked off his boots and tugged his shirt over his head.
Then had come the swift flash below him of Ralph's white, imploring face – and the leap.
For a second the current, as he struck it, seemed to be tearing Jack limb from limb. The undertow at the sluice caught him and dragged him down, down, and held him under the turbid water till it seemed that his head must burst open. At last, however, he was shot to the surface like a cork out of a bottle. Joyously he filled his lungs and began swimming.
As his hands struck out they encountered something.
To his intense joy, the next instant Jack found that the current had thrown its two victims, himself and Ralph Stetson, together, and none too soon.
Ralph's eyes were closed, and though he still floated, he seemed incapable of further effort.
Hardly had Jack time to note this, when the light was suddenly blotted out, as if a great curtain had been drawn across the sun. There was a mighty roaring, like that of a thousand huge cataracts in his ears, and he knew that they had entered the water tunnel.
Where would it lead them?
Fortunately, to Jack, fresh as he was, it was not hard to support Ralph, who was almost exhausted, and keep his own head above water at the same time. All that the Western boy now feared was that he would give out before they reached the mouth of the tunnel, or a still more alarming possibility which he hardly dared
