Leaving the boys to gather and talk things over in awed tones the two Mercer brothers made their way across the field in the direction of Professor Scott’s house. The gentleman mentioned had been their history teacher while they were in grammar school, and they knew him quite well, so they had no great fears as to the outcome. No one had appeared at the window or at the doors, and Jim supposed that the professor was not at home.
“I guess not,” Don returned, “or he would surely have appeared by now. But we’ll go over and see, and if he isn’t we’ll leave a note and tell him who did it, and offer to pay for it.”
While the Mercer boys are making their way across the field something may be said as to who they were. Both boys, fine, manly chaps, were the sons of a wealthy lumber man of Bridgewater, Maine. They had lived the life of healthy young men whose interests were centered in worthwhile things. Of late they had had some adventurous events in their lives, some of which were related in the first volume of this series, The Mercer Boys’ Cruise in the Lassie, when they ran down a marine bandit gang, and later when solving a baffling mystery at the military school, details of which were related in the second volume entitled The Mercer Boys at Woodcrest. Together with their comrade, Terry Mackson, they had faced many perils and adventures, and now they were home to spend, as they thought, a comparatively dull vacation. Just how deeply mistaken they were in their thought will be found later.
They entered the front yard of Professor Scott’s house and walked around to the side, where the broken window faced toward the empty lot. There appeared to be no one at home, but when they came opposite to the window Don raised himself slightly on his toes and looked in. Then he dropped down again and looked at Jim in astonishment.
“The professor is at home,” he said, in a low tone. “He’s sitting there, reading a letter!”
“Reading a letter?” asked Jim, amazed.
“Yes,” answered his brother. “Look in.”
Jim raised himself and looked in the window. A tall man with bushy white hair and a thick iron gray beard was seated at the desk in what appeared to be a study, busily engaged in reading a letter. Near him, almost at his feet, lay the boys’ ball, and fragments of broken glass littered the floor. The professor was apparently deeply absorbed in his letter.
“Well, what do you know about that!” exclaimed Jim, softly. “Doesn’t even seem to know that the window is broken! We always knew that he was somewhat absent-minded, but I thought he was more responsible than that!”
Before Don could reply there was a stir in the room and the next minute the professor came to the window and looked down at them. He still held what appeared to be a lengthy letter in his hand, and he recognized them.