The tests proved a severe strain on many of the boys, and Dave was glad when they were over. What the standing of each student was would not be known until later.
"Now I'd like to go skating," said he to Roger, but this could not be, for warm weather had set in and the ice and snow were rapidly passing away. That night it rained, and this made everything outside very sloppy.
Dave went to bed early, for he was tired out. He slept soundly for several hours and then awoke with a start, for something had brushed his face. He sat up, and was just in time to see a form gliding from the dormitory.
"Hello! what can that mean?" he murmured to himself, and then he sprang up. "Guess I'll investigate." And then, putting on a pair of slippers and donning a long overcoat that was handy, he made after the person who had just disappeared.
When Dave reached the hallway he saw, by a dim light that was burning, a form at the lower end, moving toward a back stairs. An instant later the form glided up the stairs toward the third floor of the school building. The form was in white, and Dave knew it must be one of the students in his nightdress.
"Something is going on," he thought. "Wonder if that is Phil or Roger?"
Curious to learn what the midnight prowler was up to, Dave followed the unknown to the third story of the building. He saw the fellow walk to a side hall. Here it was almost dark, for the servants' rooms were in that part of the building. He stopped and listened and heard an odd creaking and a scraping sound. Then he went forward once more.
Turning into the side hall, a gust of cold wind struck him. He knew it came from overhead, and then he remembered that at the end of the side hall was a ladder leading to a scuttle of the roof. The scuttle had been thrown open, and wind and rain were coming down through the opening.
Dave's curiosity was now excited to the top pitch. He felt sure that the servants had not left the scuttle open on retiring or that it had been blown open by the wind. Consequently, the midnight prowler must have opened it, and if so, for what purpose excepting to get out on the wet and slippery roof?
Suddenly an idea flashed into Dave's mind, and without further ado he ran to the ladder and mounted it with all speed. At the top he thrust his head through the scuttle opening and looked around that portion of the school roof which was visible from that point.