The professor looked down at Terry, who stared in puzzled wonder at Don. “That is very strange. He doesn’t appear to know you.”

“Perhaps he has been hit on the head,” suggested Jim, coming forward.

“This is fierce,” said Don, worry on his face. “Terry, don’t you know me?”

“‘Shoot if you must this old gray head, but I don’t remember you, she said,’” was the unexpected reply, and the corners of his mouth, which had been quivering, expanded. The professor burst into a roar of laughter.

The Mercer boys stood for a moment rooted to the spot, while Terry and the professor laughed in unrestrained glee. After the first moment of disgust their eyes narrowed and two determined chins were thrust forward.

“Jim,” said Don, quietly. “Put out the light. I don’t want the world to witness the awful thing that is going to happen here!”

“Put it out yourself!” retorted Jim. “I am due for a first class murder, and I’m late now!”

And with that the two brothers threw themselves in mock fury onto the body of their laughing friend and bore him to the floor, where they punched him soundly, finding their task an easy one, for the red-headed boy was weak from laughter. When they had tired themselves they jerked him up and pushed him into the chair, the professor enjoying it all hugely.

“That was positively the most low trick I ever saw,” declared Don disgustedly.

“I’d like to have a look at the brain that would think of such a thing,” chimed in Jim.