Precisely at eight o'clock the three friends, warmly and conveniently clad, with their keen-edged skates securely fastened, glided gracefully up-stream, the mother standing on the porch of her home and watching the figures as they vanished in the moonlight. She was smiling, but in her heart was a misgiving such as she had not felt before, when her children were starting off for an evening's enjoyment. The minute they were beyond sight she sighed, and, turning about, resumed her seat by the table in the centre of the sitting-room, where, as the lamplight fell upon her pale face, she strove to drive away the disquieting thoughts that would not leave her. It was a pleasing sight as the three young people, the picture of life, health and joyous spirits, side by side, laughing, jesting, and with never a thought of danger, moved out to the middle of the river and then sped toward its source, with the easy, beautiful movement which in the accomplished skater is the ideal of grace. The motion seemingly was attended with no effort, and could be maintained for hours with little fatigue. The small river, to which allusion has been made, was one hundred yards in width at the point where they passed out upon its surface. This width naturally decreased as they ascended, but the decrease was so gradual that at Wolf Glen, fifteen miles away, the breadth was fully three-fourths of the width opposite the Whitney home. Occasionally, too, the channel widened to double or triple its usual extent, but those places were few in number, and did not continue long. They marked a shallowing of the current and suggested in appearance a lake. There were other spots where this tributary itself received others. Sometimes the open space would show on the right, and further on another on the left indicated where a creek debouched into the stream, in its search for the ocean, the great depository of most of the rivers of the globe. The trees, denuded of vegetation, projected their bare limbs into the crystalline air, and here and there, where they leaned over the banks, were thrown in relief against the moonlit sky beyond. The moon itself was nearly in the zenith, and the reflected gleam from the glassy surface made the light almost like that of day. Along the shore, however, the shadows were so gloomy and threatening that Monteith Sterry more than once gave a slight shudder and reached his mittened hand down to his side to make sure his weapon was in place. The course was sinuous from the beginning, winding in and out so continuously that the length of the stream must have been double that of the straight line extending over the same course. Some of these turnings were abrupt, and there were long, sweeping curves with a view extending several hundred yards. They were spinning around one of these, when Sterry uttered an exclamation: "I'm disappointed!" "Why?" inquired Jennie, at his elbow.