“That shelf under there takes out, so as to give room to get through,” explained Marchmont, proudly; “and the box on the shelf prevents the old lady from getting on to the game.”

Wolcott gazed into the dark, mysterious hole in amazement. The job was cleverly done, and yet of what use could the hole be?

“Who rooms underneath,” he asked; “Salter?”

Marchmont nodded.

“I didn’t know you were so thick with him.”

“I’m not. I don’t care a rap for him. This isn’t meant for his benefit, it’s for my own. Salter’s a virtuous chump, who’s always in at ten o’clock, and always tells the truth when he reports. He’s a good little boy, but not good enough to volunteer information. If I come down into his closet and go out his window, he isn’t bound to tell of it, and of course nobody asks him whether his ceiling’s tight.”

“I still don’t see much use for it,” said Wolcott, slowly. “If I am out after ten, I simply say so, and tell why; I don’t mind that.”

“Supposing you don’t want to tell why,” replied Marchmont, dryly, as he replaced the oil-cloth and led the way back into his room. “Supposing you’re on probation or study hours or something of that sort, and want to be out. All you have to do is to say good night to Mrs. Winter, lock your door, and you have your evening.”

“You’ll have a chance to use the thing pretty soon, if you’re only waiting for probation,” said Wolcott, laughing. “You’re getting below my level in some studies, and that’s mighty close to the danger line.”

“If I never get below your level, I shan’t care,” returned Marchmont. “I’m tutoring now with Haynes White. He’ll probably pull me up before probation comes. If he doesn’t, let it come. I’ve been there before.”