"Who are you?" asked the Major in dismay.
"Professor Blyth."
"The devil!" Anstruther ejaculated.
"No, sir—Professor Blyth," came the response.
"Where are you?" asked the Major.
"I am in the room at the end of the corridor. I can observe the door of your room from where I stand, and I have a loaded revolver in my hand."
"What are you going to do?"
"That depends upon you. I can either send for the police, and give you in charge, or I can take scientific observations with your assistance—whichever you prefer."
"What do you mean by scientific observations?"
"You are locked up in a room twelve feet square with an ounce of radium."