“There goes something!” cried Tom presently.  “Sam, did you see it?”

“I saw something, but it disappeared before I could make out what it was.”

The object had crossed their path a hundred feet ahead of them.  Now it reappeared somewhat closer, and both boys saw that it was a lean and hungry-looking wolf.

“A wolf!” cried Sam.

“Wonder if I hadn’t better shoot him,” said Tom, unslinging his gun.

“Better save your powder, Tom.  I don’t believe he’ll attack us—­at least not while it is light.”

“A shot might bring an answering signal from Dick,” went on Tom suddenly.  “What fools we have been, not to think of that before!”

The wolf kept hidden and Tom did not shoot, expecting to see the beast reappear at any instant.  On they went, keeping an eye on the bushes and trees on both sides of them.  Once they heard the patter of the wolf’s feet on a stretch of bare rocks, but that was all.

“I’ll fire a shot, anyway,” said Tom at last, and aimed in the direction where they had heard the sounds last.  To his intense surprise a yelp and a snarl followed.

“Great Caesar!  I hit him after all,” began Tom, and then leaped back.  “Look out, Sam, he’s coming for us!”

Tom was right.  The wolf, wounded in the left flank, had suddenly appeared.  His eyes blazed with pain and fury, and he made as if to spring upon the boys.

Tom was in front of the sled and Sam behind it.  With a quick leap Tom cleared the load and took up a position beside the youngest Rover.

The wolf made the leap, but stopped short on the top of the load.  As he prepared to spring again Tom swung his gun around by the barrel and hit the wolf a smart rap on the head.  The animal rolled over on the ground.

“Shoot him, Sam!”

“I will, if I can!” came from Sam, who had now unslung his gun.  Taking a quick aim, he fired.

The shot proved a good one, for it took the wolf directly in the neck, just as he was scrambling to rise.  Again he gave a yelp, and then began to turn over and over in his intense pain.  Of a sudden he leaped up and landed on Tom’s shoulder.

For the instant poor Tom thought his last moment had come.  But as the beast landed Sam struck it with his gun, and down it went once more, snarling viciously.  Then it rolled and tossed until some brush was gained, when it managed to hide itself and crawl away, seriously, if not mortally, wounded.

“He’s gone!” came from Sam.

“Well, don’t go after him,” panted Tom.  “Let him go and welcome.  I never want to see him again.”

“Nor I.”

Both reloaded with all haste—­having learned years before that it is foolish to remain in the wilds with an empty firearm.  Then they waited, to see if the wolf would return.

“Hark!” cried Sam.  “Did you hear that shot, Tom?”

“I did.  I think it came from that direction.”  And Tom pointed with his hand.