What thoughts fled through Frank Merriwell's brain? Surely he was besieged by uncanny fancies, but never in all his life was he more on the alert. The very air of mystery that surrounded him was a stimulant. He had solved many mysteries, and now he was determined to solve this one.

Down the slope in the shadows of the dark woods below there was a rustling sound. Quick as a flash, Merriwell wheeled, rifle in hand, and bounded in that direction.

Browning did not care to be left there alone beside that grave, and he followed Frank in a hurry. He saw Merry disappear amid the trees, heard a sudden chattering,

and then there was a flash of fire and the clear report of a rifle. Frank had fired at something while he was on the run.

The big Yale man crashed into the woods and came upon his friend, who was stooping to pick up a dead squirrel.

"I rather think this fellow made the rustling that seemed to come from the grave," said Merry. "I was deceived by my ears, that is all. As I ran in under the trees here I could not resist the temptation to take a shot at him, for he was running, too. Now," he slowly added, gazing sadly at the dead squirrel, "I wish I had not fired."

"Oh, it's nothing but a squirrel," said Bruce. "If I could make such a shot as that I'd be proud of it."

"I am not proud, only sorry," said Frank, as he gently placed the squirrel on a soft bed of moss. "Look at the little fellow, Bruce! A few moments ago he was full of life, happy and free; now he is dead, killed by a cruel brute of a man! I didn't think I'd hit him, but that is no excuse. I ought not to have tried. Somewhere he has a home, a nest, a mate, perhaps little ones. He'll never return to his soft nest, never again will he scamper through the woods, leaping from bough to bough, playing hide-and-seek through the brush and the leaves. He is dead, and I killed him. Bruce, this one thoughtless, hasty act of mine lies like a sore weight on my conscience. I'll not forget it in a week. It will trouble me—it will haunt me."

Frank's voice was rather husky with emotion and his handsome face betrayed his deep feeling of sorrow, and Bruce Browning, who was not cruel or hard-hearted, but who would have killed a squirrel and never given it a second thought, now began to realize that there might be something wrong in the act.