"Thirty-five," replied the Major. "Nothing like the truth in an emergency," he added to himself.

"John Smithers, aged thirty-five," was repeated. "Late occupation?"

"Soldier."

"Good. Very good. Late occupation, soldier. Any pension?"

"Yes."

"What a fool you are to risk it for a bit of radium."

The Major stepped back in sheer amazement. "What did you say?" he asked.

"Whatever made you risk your pension for a bit of radium?"

"Don't know what you mean."

"Then I'll explain. You are a thief, locked up in Professor Blyth's dark room. Isn't that so?"