Although he fired his own rifle repeatedly, he got no response, and he finally concluded that Mark was playing a practical joke, and had ridden home after firing his gun without waiting for him.
Thus thinking, he turned his own horse's head towards home, and an hour later reached the house.
He found Mark's horse standing at the stable door in a lather of foam, and still saddled and bridled.

Then it flashed across him that something had happened to Mark, and, filled with a sickening dread, he hurried into the house and aroused Mr.Elmer.
"Hasn't Mark come home ?" he inquired, in a husky voice.
"No, not yet.

Isn't he with you ?" asked Mr.Elmer, in surprise.
"No; and if he isn't here something dreadful has happened to him, I'm afraid"; and then Frank hurriedly told Mr.Elmer what he knew of the events of the hunt.
"We must go in search of him at once," said Mr.Elmer, in a trembling voice, "and you must guide us as nearly as possible to the point from which you heard the shot." Hastily arousing Mr.March and Jan, and telling them to saddle the mules, Mr.Elmer went to his wife, who was inquiring anxiously what had happened, and told her that Mark was lost, and that they were going to find him.

The poor mother begged to be allowed to go too; but assuring her that this was impossible, and telling Ruth to comfort her mother as well as she could, Mr.Elmer hurried away, mounted Mark's horse, and the party rode off.
Frank knew the country so well that he had no difficulty in guiding them to the spot where he and Mark had separated.

From here they followed the star that Frank had pointed out to Mark, and riding abreast, but about a hundred feet apart, they kept up a continual shouting, and occasionally fired a gun, but got no answer.
At length Mr.March detected a glimmer of light on the ground, and dismounting, found a few charred sticks, one of which still glowed with a coal of fire.
"Halloo!" he shouted; "here's where Mark emptied his fire-pan." They all gathered around, and having brought a supply of light-wood splinters with which to make torches, they each lighted one of these, and began a careful search for further evidences of the missing boy.
A shout from Jan brought them to him, and he showed the broken fire-pan which he had just picked up.
A little farther search revealed the deep imprints of the horse's hoofs when he had plunged and reared as the burning brands fell on his back; and then, step by step, often losing it, but recovering it again, they followed the trail until they came upon the rifle lying on the ground, cold and wet with the night dew.
Mr.March, holding his torch high above his head, took a step in advance of the others as they were examining the rifle, and uttered a cry of horror.
"A sink-hole! Good heavens! the boy is down there!" A cold chill went through his hearers at these words, and they gathered close to the edge of the opening and peered into its black depths.
"We must know beyond a doubt whether or not he is down there before we leave this place," said Mr.Elmer, with forced composure, "and we must have a rope.