"The lady has not returned, sir!"

"Anything from Gordon and Duff?"

The telephone on the desk whirred. The Chief lifted the receiver.

"Yes. Oh, it's you, Gordon? No, you can say it now: this is a private line."

He listened at the receiver for a couple of minutes. The room was very still.

"All right, come to the office at once!"

The Chief hung up the receiver and turned to the Admiral.

"She's given us the slip for the moment!" he said. "That was Gordon speaking. He and Duff have been shadowing our lady friend out of doors for days. She left the hotel on foot after lunch this afternoon with my two fellows in her wake. There was a bit of a crush on the pavement near Charing Cross and Duff was pushed into the roadway and run over by a motor-'bus. In the confusion Gordon lost the trail. He's wasted all this time trying to pick it up again instead of reporting to me at once."