He laid down the receiver. He looked around him like a man in a nightmare.

“The taxicab is still waiting, sir,” Craig reminded him.

“That is most fortunate,” the Professor pronounced. “I remember now that I had no change with which to pay him. I must go back. Look after my brother. And, Craig, telephone at once to Mr. Sanford Quest. Ask him to meet me at the museum in twenty minutes. Tell him that nothing must stand in the way. Do you hear?”

The man hesitated. There was protest in his face.

“Mr. Sanford Quest, sir?” he muttered, as he followed his master down the hall.

“The great criminologist,” the Professor explained eagerly. “Certainly! Why do you hesitate?”

“I was wondering, sir,” Craig began.

The Professor waved his servant on one side.

“Do as you are told,” he ordered. “Do as you are told, Craig. You others—you do not realise. You cannot understand what this means. Tell the taxi man to drive to the museum. I am overcome.”

The taxicab man drove off, glad enough to have a return fare. In about half-an-hour’s time the Professor strode up the steps of the museum and hurried into the office. There was a little crowd of officials there whom the curator at once dismissed. He rose slowly to his feet. His manner was grave but bewildered.