The wrecking crew with their big derrick and other tools had not yet arrived in the cut where the stalled west-bound train, on which rode the Bunker family, had stopped. But the section gang had shoveled away the dirt and gravel from the east-bound track.

Russ and Rose and Margy and Mun Bun had found plenty to interest them in watching the shovelers and in listening to the men passengers talking with daddy and some of the train crew. Finally Mun Bun expressed a desire to go back into the car, and Rose went with him. As they were climbing the steps into the vestibule a brakeman came running forward along the cinder path beside the tracks.

"All aboard! Back into the cars, people!" he shouted. "We're going to steam back. Get aboard!"

Russ and Margy being the only Bunker children in sight, Mr. Bunker "shooed" them back to the Pullman car. He saw Rose and Mun Bun disappearing up the high steps, and he presumed Laddie and Violet were ahead. The train had started and the four children and daddy came to mother's seat before it was discovered that there were two little Bunkers missing.

"Oh, Charles!" gasped Mrs. Bunker. "Where are they?" The train began to move more rapidly. "They are left behind!"

"No, Amy, I don't think so," Mr. Bunker told her soothingly. "I looked all about before I got aboard and there wasn't a chick nor child in sight. I was one of the last passengers to get aboard. The section men had even got upon their handcar and were pumping away up the east-bound track. There is not a soul left at that place."

"Then where are they?" cried Mother Bunker, without being relieved in the least by his statement.

"I think they are aboard the train—somewhere. They got into the wrong car by mistake. We will look for them," said Mr. Bunker.

So he went forward, while Russ started back through the rear cars, both looking and asking for the twins. As we quite well know, Vi and Laddie were not aboard the train at all, and the others found this to be a fact within a very few minutes. Back daddy and Russ came to the rest of the family.

"I knew they were left behind!" Mother Bunker declared again, and this time nobody tried to reassure her.

Her alarm was shared by daddy and the older children. Even Margy began to cry a little, although, ordinarily, she wasn't much of a cry-baby. She wanted to know if they had to go on to Cowboy Jack's and leave Vi and Laddie behind them—and if they would never find them again.

"Of course we'll find them," Rose assured the little girl. "They aren't really lost. They just missed the train."

Daddy hurried to find their conductor and talk with him. He came back with the news that the train was only going to run back a few miles to where there was a cross-over switch, and then the train would steam back again into the cut on the east-bound track. The conductor promised to stop there so Mr. Bunker could look for the lost children.

But Mother Bunker was much alarmed, and the children kept very quiet and talked in whispers. Although Russ and Rose spoke cheerfully about it to the other children, they were old enough to know that something really dreadful might have happened to the twins.

"I guess nobody could have run off with them," whispered Russ to his sister.

"Oh, no! There were no Gypsies or tramps anywhere about. Anyway, we didn't see any."

"They weren't carried off. They walked off," said Russ decidedly. "Maybe they will be back again waiting for the train."

They all hoped this would be the fact. The train finally stopped and then steamed ahead again and ran on to the east-bound track that had been cleared of all other traffic so that the passenger train could get around the landslide. Mr. Bunker and Russ went out into the vestibule so as to jump off the train the moment it stopped in the cut. The conductor and one of the brakemen got off too, but other passengers were warned to remain aboard. The train could not halt here for long.

Russ ran around the big rock that had fallen on the other track, and up the road a way. But there was no sign of Vi and Laddie. Mr. Bunker saw the path up the bank, and he climbed just as the twins had and reached the top.

The big pasture was then revealed to the anxious father; but Vi and Laddie were nowhere in view. Why! Daddy Bunker didn't even see the chipmunk Laddie and his sister had chased. Daddy Bunker shouted and shouted. If the twins had been within sound of his voice they surely would have answered. But no answer came.

"You'll have to come down from there, Mr. Bunker!" called the conductor of the train. "We can't wait any longer. We're holding up traffic as it is."

So Mr. Bunker came down to the railroad bed, very much worried and hating dreadfully to go back and tell Mother Bunker and the rest of the little Bunkers that the twins were not to be found.

There was nothing else to be done. Where the twins could have disappeared to was a mystery. And just what he should do to trace Vi and Laddie their father could not at that moment imagine.

The train started again, but ran slowly. Mrs. Bunker did not weep as Margy did, and as Rose herself was inclined to do. But she was very pale and she looked at her husband anxiously.

"My poor babies!" she said. "I think we will all have to get off the train at the next station, Charles, and wait until Vi and Laddie are found."

Daddy Bunker could not say "no" to this, for he did not see any better plan. Of course they could not go on to Cowboy Jack's ranch and leave Vi and Laddie behind.

The other passengers in the car took much interest in the Bunkers' trouble. Most of the men and women had grown fond of Violet, in spite of her inquisitiveness, and all admired Laddie Bunker. It seemed a really terrible thing that the two should have become separated from their parents and the other children.

"Something is always happening to us Bunkers," confessed Russ. "But what happens isn't often as bad as this. I don't see what Vi and Laddie could have been thinking of."

We know, however, that the twins had been thinking of nothing but gathering flowers and chasing a chipmunk until that train whistle had sounded. How the twins did run then across the pasture and up to the very verge of the high bank overlooking the railroad cut!

"Oh, the train's gone!" shrieked Vi, when she first looked down.

"And the workmen are gone too," gasped Laddie.

There was nobody left in the cut, and both the train and the handcar on which the section hands had traveled, were out of sight. It was the loneliest place that the twins had ever seen!

"Now, see what we've done," complained Vi, between her sobs. "We ran away and lost mother and daddy and the others. They've gone on to Cowboy Jack's and left us here."

"Then we didn't run away from them," Laddie said more sturdily. "They ran away from us."

"That doesn't make any difference," complained his sister. "We—we're lost and can't be found."

"Say!" cried Laddie suddenly, "how do you s'pose that train hopped over that rock?"

This point interested Vi at once. It was a most astonishing thing. If the train had gone on to Cowboy Jack's, it surely had got over that big rock in a most wonderful way.

"How did it get over the rock?" Vi began. "Did it fly over? I never saw the wings on that engine, did you? And if the engine did fly over, it couldn't have dragged the cars with it, could it?"

"Oh, don't, Vi!" begged Laddie, much puzzled. "I couldn't tell you all that. Maybe they had some way of lifting the train around the rock. Anyway, it's gone."

"And—and—and what shall we do?" began Vi, almost ready to cry again.

"We have just got to follow on behind it. I guess daddy will miss us and get off and come back to look for us after a while."

"Do you suppose he will?"

"Yes," said Laddie with more confidence, as he thought of his kind and thoughtful father. "I am sure he will, Vi. Daddy wouldn't leave us alone on the railroad with no place to go and nothing to eat."

At this Vi was reminded that they had not eaten since breakfast, and although it was not yet noon, she declared that she was starving!

"You can't be starving yet," Laddie told her, with scorn. "We haven't been lost from the train long enough for you to be starving, Violet Bunker."

"Well, Laddie, I just know we will starve here if the train doesn't come back for us."

"Maybe another train will come along and we can buy something from the candy boy. You 'member the candy boy on our train? I've got ten cents in my pocket."

"Oh, have you? That will buy four lollipops—two for you and two for me. I guess I wouldn't starve so soon if I had two lollipops," admitted Vi.

"I guess you won't starve," Laddie told her without much sympathy. "Now we must climb down to the tracks and start after daddy's train."

"Do you suppose we can catch it? Will it stop and wait when daddy finds out we're not on it? And are you sure he'll come back looking for us? Shall we get supper, do you s'pose, Laddie, just as soon as we get on the train? For I'm awfully hungry!"

Her twin could not answer. Like the other Bunkers, he was nonplussed by some of Vi's questions. Nor did he have much idea of how Daddy Bunker was going to stop the train, which he supposed had gone ahead, and return to meet Vi and him trudging along the railroad tracks.