Since plenty of time was at command, they continued their easy pace, passing over several long and comparatively straight stretches of frozen water, around sharp bends, beyond another expansion of the stream, in front of a couple of natural openings, and finally, while it lacked considerable of ten o'clock, they rounded to in front of a mass of gray towering rocks on the right bank of the stream, and, skating close into shore, sat down on a bowlder which obtruded several feet above the ice. They were at the extremity of their excursion. These collective rocks bore the name of Wolf Glen, the legend being that at some time in the past a horde of wolves made their headquarters there, and, when the winters were unusually severe, held the surrounding country in what might be called a reign of terror. They had not yet wholly disappeared, but little fear of them was felt. The friends could not be called tired, though, after skating fifteen miles, the rest on the stone was grateful. They sat for half an hour chatting, laughing, and as merry as when they started from home. The sky was still unclouded, but the moon had passed beyond the zenith. A wall of shadow was thrown out from one of the banks, except for occasional short distances, where the course of the stream was directly toward or from the orb. When Sterry again glanced at his watch it was a few minutes past ten. They had rested longer than any one suspected. "Mother won't look for us before midnight," remarked Fred, "and we can easily make it in that time." "She was so anxious," said the sister, who, despite her light-heartedness, was more thoughtful than her brother, "that I would like to please her by getting back sooner than she expects." "We have only to keep up this pace to do it," said Monteith, "for we have been resting fully a half hour--" He paused abruptly. From some point in the wintry wilderness came a dismal, resounding wail, apparently a mile distant. "What is that?" asked Monteith, less accustomed to the Maine woods than his companions. "It is the cry of a wolf," replied Fred; "I have heard it many times when hunting alone or with father." "It isn't the most cheerful voice of the night," commented the young Bostonian, who, as yet never dreamed of connecting it with any peril to themselves. And then he sang: Yes, the war whoop of the Indian may produce a pleasant thrill When mellowed by the distance that one feels increasing still; And the shrilling of the whistle from the engine's brazen snout May have minor tones of music, though I never found it out. The verse was hardly finished when the howl was repeated. "It is hard to tell from what point it comes," observed Fred, "but I think it is on the right shore as we go back." "Do you imagine it is far from the river?" inquired Monteith. "I think not, but I may be mistaken."