Down the rocky slope, toward the little settlement on the flats below the dam, rode Jack. He thought rapidly. If he could beat the flood, there would be time to warn the sleeping population so they could flee to the hills. There were not many who had their homes in the danger zone, not more than twenty-five families.

"I'll wake some of 'em up," Jack reflected, "and then they can warn the others. I don't imagine they'll have time to save anything. Too bad! But that dam is certainly going."

The rain came pelting down once more, the drops stinging in Jack's face. He tried to listen, to ascertain if he could hear the roar of the waters that would indicate that the dam had already gone out, but all he could catch was the splash of the rain.

Jack's course was along the now turbulent stream that was formed from the overflow of the pent-up waters. In normal times this was but a mere brook, most of the waters being led off through a pipe line to supply a distant irrigation scheme. But now there was so much water that not only was the pipe line filled, but the overflow from the dam had turned the brook into a river.

"The people ought to have seen the danger, and gotten out before this," reflected Jack, "but perhaps they haven't. Well, I'll do my best to save 'em!"

On galloped the faithful pony. Jack wished he could put the mail and express stuff somewhere until he could conclude his ride for life, but it would not be safe to leave it anywhere. Fortunately, he had not much of a load that night.

To Jack it seemed that he never would reach the little town, nor see the lights of the first cabin loom into sight.

"That is there'll be lights if the folks are up," mused Jack, "and I hope some of them are. There'll be some tall scrambling if I have to get 'em all up out of bed."

The rain was a perfect torrent now, and the lad realized that, with all this additional water falling into the reservoir, and with what it would receive from the swollen mountain streams flowing into it, the dam would be further endangered.

The pony slipped and almost fell as he went around a bad turn, where the trail was filled with rocks.

"Look out there, Sunger!" Jack cautioned him, as he pulled up the faithful animal "This is no time to fall!"

But Sunger recovered himself, and galloped on.

Suddenly a light flashed into view, then another.

"A house!" exclaimed Jack. "The first one. Now for the alarm!"

He rode up to the door, glad in his heart that the light was burning.

"Though that doesn't indicate that they're awake," the lad mused.

He pounded on the door, not getting out of the saddle.

"Get up! Get up!" he cried. "The dam will give way in a moment! Get up, and help give the alarm!"

There was a moment of silence, broken only by the patter of the rain.

"Hurry! Hurry!" Jack cried, again pounding on the portal.

This time he heard, after a wait of a few seconds, some one moving in the house, then a sleepy voice demanded:

"What is it? What's the matter? Who's there?"

"Never mind who I am!" Jack replied. "It's the pony express rider, between Golden Crossing and Rainbow Ridge, if you have to know. But the dam is giving way! It may have gone out now! There'll be the biggest kind of flood on these flats in half an hour! Get up! Take to the hills!"

The door was thrown open, revealing a man wrapped in a blanket He seemed just to have gotten up out of bed.

"What's that?" he inquired, sleepily.

Jack repeated his warning. The man understood now. He rushed back in to the room.

"Come on, 'Mandy!" he yelled. "Git the children! Hustle into what clothes you can! We've got to skip! The dam is going out! Quick now!"

"Warn the others nearest you!" Jack cried, as he turned Sunger away from the house. "I'm going to ride on down below and give the alarm."

"I will!" the man answered. "You've probably saved our lives!"

A woman could be heard crying, and children were screaming in fear within the house, but Jack could not stay for that. There were others to warn.

On he rode, going past without pause the few houses near that of the man he had first called. Jack depended on him to give the alarm to his neighbors.

But the lad called at other cabins, repeating his warning. Some folk he had difficulty in arousing, but the news soon spread, and in a short time the whole settlement was on the alert.

As Jack knocked on the door of the last house, farthest removed from the upper end of the settlement, he heard far off a dull boom like the reverberation of an explosion.

"There goes the dam!" cried Jack. "Now the flood will come!"

But the people had been warned in time. They had no chance to save anything save their most easily-carried belongings, and with these they fled to high ground.

The noise Jack had heard was the breaking of the dam, and a little later a great wall of water swept down the narrow valley. It carried everything before it, sweeping away the frail cabins in its path. But there was no loss of human life, thanks to the brave pony rider.

Jack wished he could stay and help the unfortunates, but he had other duties. And, anyway, the residents on the higher ground, who were in no danger, came to the relief of their neighbors. Houses were thrown open to those whose homes had been swept away, and the refugees were given clothing, food and shelter.

The flood did not last long, for the reservoir was soon emptied. But in that short time it did great damage; that is comparatively great, for the cabins were mostly those of poor persons.

The mass of water gradually subsided, though the heavy rains had made a river of the mountain brook, and it was several days before it went back to its normal level. Then the work of repairing the damage of the flood was taken up.

When Jack saw, that night, that he had done all he could, he turned back on the trail, for the mail must not be delayed longer than could be helped, and already nearly three hours had been lost.

It was almost morning when he rode into Rainbow Ridge with the first news of the burst dam. He made light of his own part in the affair, but that came out later, and much honor was paid the lad. He bore his honors modestly, however, and the greatest praise—or what he considered such—was when his father said:

"I'm proud of you, Jack, my boy!"

Relief for the unfortunate flood victims was sent both from Rainbow Ridge and Golden Crossing, and when Jennie heard of the disaster she insisted on doing up some of her own clothing and forwarding it to some of the girls who had lost theirs.

Every one helped, as is always the case at a time like that, and though many families lost everything, still there was no mourning for lives that never could be given back. Jack had provided against that by his brave ride.

It was two weeks after the flood, and now the mountains were calm and peaceful again. The long season of rain had passed, and the weather was glorious. Jack enjoyed every moment of it as he rode the trail.

"It certainly is a great life!" he reflected. "I'm glad the way is so rough, otherwise they'd be wanting me to use a motor-cycle or an automobile. But none of them for me, while I have you, Sunger!"

The pony whinnied his answer, as Jack patted him on the neck.

"Well, anything big to-day, Jennie?" he asked, as he rode up to the Golden Crossing office one afternoon. "Anything important? Why, what's the matter?" he asked in some concern. "You look worried."

"I am, Jack," she said, and she did not answer his smile.

"What about? Your mother isn't ill; is she? You haven't lost any registered letters?"

"No, it isn't that, but a post office inspector has been here, asking me a lot of questions. He intimated that things weren't being done right, and he's coming back in an hour to check up my accounts."

"Well, I suppose they have to do what they're hired for. Was he mean or ugly?"

"No, but he seemed terribly in earnest. And suppose my accounts aren't exactly right? I may have made little mistakes. Then he'll report me and I'll lose my office. Oh, Jack, I couldn't bear that!"

"Don't worry," Jack soothed her. "I'll stay and have a talk with this inspector. Maybe I can help straighten matters out, if they're a bit wrong. You say he is coming back in an hour?"

"Yes, and the time is nearly up. There he is now."

Jack looked out, and a strange feeling came over him as he saw a large man, on an unusually high horse riding up to the post office.

"Is he the inspector?" asked the pony rider.

"Yes," Jennie answered.

Jack shut his teeth grimly, and a strange look came over his face.