So I reckoned that his camouflage must correspond to this little idiosyncrasy.

Being a Boche agent, he wouldn't pretend to be a hearty patriot, an honest old blood-and-bones Tory.

That would be only the Single Bluff.

I considered that he would be a pacifist, cunning enough just to keep inside the law, but with the eyes of the police on him.

He would write books which would not be allowed to be exported.