"Indeed, sir. And who did you get that valuable piece of information from?"
"From my friend the policeman that I told you about. The house is shut up for a few days and the authorities have been informed of the fact. I have been all around the house and it is as silent as the grave."
"Well, that might be merely a blind, after all," Field said cheerfully. "When did they go?"
"So far as I can gather from Macklin, they departed early this morning."
Field chuckled but said nothing. A little while later there was a thud of heavy boots on the pavement, and Macklin and his sergeant came, together. The latter was about to say something but Field produced his card and the effect was instantaneous.
"No, we don't want any assistance at all," the Scotland Yard official said. "All you can do is to go about
your work as if nothing was taking place. You may notice something suspicious presently at No. 100, across the road, but you are to ignore it. You understand?"
The sergeant nodded and touched his helmet; he understood perfectly well. The two passed on together and the sham sailors crossed the road. Very quietly Field proceeded to the back of the house. It was a little dark here, and he guided himself by pressing his fingers to the walls. Presently he stopped, and a low chuckle came from his lips.
"Discovery the first, sir," he said. "Press your hand on the wall here. What do you notice?"
But Berrington noticed nothing beyond the fact that the wall was quite warm. He said so, and the inspector chuckled once more. He seemed to be pleased about something.