'That's most curious!' I said, in reply to Theed. 'Your father seems to be having quite a lively time at night out there!'
'Yes. He does, sir. He's convinced that somebody is watching to find out what's going on—spies, he declares.'
'No, no, Theed,' I laughed, in order to hearten him. 'There's far too much bunkum talked about spies, and far too many sensational rumours on every hand. Tell your father that he's becoming nervous. Surely he ought not to be after all his long police service!'
I only uttered those words for effect. I knew that Theed would bully the old man, and tell him that he was suffering from nerves. Every son loves to jeer at his father, be he peer or peasant.
I passed into my room and took up the telephone.
In a few moments I was on to my friend Professor Appleton, the Director of the National Physical Laboratory, that department which, for years, had studied aeronautics.
'I don't follow you, Mr. Munro,' he said, when I told him the facts. 'What name do you say?'
'Hale,' was my reply. 'H-a-l-e,' and I spelt it.
'We've nobody of that name. There must surely be some mistake!'
'But he came with a visiting-card,' I said. 'He went to the firm of engineers who are making certain alterations in my monoplane, and demanded of the foreman the right to examine what was in progress. He told them at Willesden that he was an official
