“ ‘A robbery has been committed,’ I gasped. ‘A document of immense value has been stolen from the Foreign Office. Has anyone passed this way?’

“ ‘I have been standing here for a quarter of an hour, sir,’ said he; ‘only one person has passed during that time⁠—a woman, tall and elderly, with a Paisley shawl.’

“ ‘Ah, that is only my wife,’ cried the commissionnaire; ‘has no one else passed?’

“ ‘No one.’

“ ‘Then it must be the other way that the thief took,’ cried the fellow, tugging at my sleeve.

“ ‘But I was not satisfied, and the attempts which he made to draw me away increased my suspicions.

“ ‘Which way did the woman go?’ I cried.

“ ‘I don’t know, sir. I noticed her pass, but I had no special reason for watching her. She seemed to be in a hurry.’