'May I ask you to keep it to yourself, sir, if I tell you something?' he said at last.

'What do you mean?'

'I'm a detective.'

'What!'

'A Pinkerton's man, Mr Burns.'

I felt like one who sees the 'danger' board over thin ice. But for this information, who knew what rash move I might not have made, under the assumption that the Little Nugget was unguarded? At the same time, I could not help reflecting that, if things had been complex before, they had become far more so in the light of this discovery. To spirit Ogden away had never struck me, since his arrival at the school, as an easy task. It seemed more difficult now than ever.

I had the sense to affect astonishment. I made my imitation of an innocent assistant-master astounded by the news that the butler is a detective in disguise as realistic as I was able. It appeared to be satisfactory, for he began to explain.

'I am employed by Mr Elmer Ford to guard his son. There are several parties after that boy, Mr Burns. Naturally he is a considerable prize. Mr Ford would pay a large sum to get back his only son if he were kidnapped. So it stands to reason he takes precautions.'

'Does Mr Abney know what you are?'

'No, sir. Mr Abney thinks I am an ordinary butler. You are the only person who knows, and I have only told you because you have happened to catch me in a rather queer position for a butler to be in. You will keep it to yourself, sir? It doesn't do for it to get about. These things have to be done quietly. It would be bad for the school if my presence here were advertised. The other parents wouldn't like it. They would think that their sons were in danger, you see. It would be disturbing for them. So if you will just forget what I've been telling you, Mr Burns—'