The set-up is rather Sherlockian. The hero of the piece, Angus, proposes marriage to Laura Hope, a waitress in a cake shop. However, she is not free to accept his offer. Some years previously, in a former life as a rural barmaid, two men proposed to her. The first, Smythe, was a very small man. The second, Welkin, possessed a squint. Too poilte to say no, and unwilling to give her real reasons for prevaricating, she told them she would only ever marry a man who had made his own way in the world. To her surprise, both men immediately vanished away to seek their fortunes.
Smythe has since made his fortune through the invention of a range of mechanical household devices which can be seen advertised on every street corner. He has recently written to Laura announcing his success. Meanwhile, Welkin has been haunting her.
“… it is of him that I am frightened. It is he who is all about my path. It is he who has half driven me mad. Indeed, I think he has driven me mad; for I have felt him where he could not have been, and I have heard his voice when he could not have spoken.”
Soon, Smythe turns up, and it becomes clear that Welkin has been persecuting him as well. He has been receiving threatening letters at his flat in Himalaya Mansions and believes his life to be in danger.
Angus offers to bring in his friend, the detective Flambeau (remember him? – all reformed now) to Smythe’s flat to look at the letters. He finds it a strange place, full of the inventor’s mechanical creations.
Like tailors’ dummies they were headless; and like tailors’ dummies they had a handsome unnecessary humpiness in the shoulders, and a pigeon-breasted protuberance of chest; but barring this, they were not much more like a human figure than any automatic machine at a station that is about the human height.
And there is a fresh threatening letter. Angus immediately leaves to get Flambeau, but sets a ring of men – a cleaner, a commissionaire, a policeman and a chestnut-seller – to keep an eye on Smythe’s building.
Flambeau, who was a friend of Angus, received him in a rococo artistic den behind his office, of which the ornaments were sabres, harquebuses, Eastern curiosities, flasks of Italian wine, savage cooking-pots, a plumy Persian cat, and a small dusty-looking Roman Catholic priest, who looked particularly out of place.
Flambeau and Father Brown accompany Angus through a snowfall back to Smythe’s flat, where, despite Angus’s precautions, they find the little man vanished except for a tell-tale stain of blood on the floor.
The four men watching the flats have seen nothing, even though a trail of footprints in the snow can clearly be seen going into the building.
“God!” cried Angus involuntarily, “the Invisible Man!”
Not so, as Father Brown soon demonstrates when he identifies the murderer.
There’s a lovely final sentence:
But Father Brown walked those snow-covered hills under the stars for many hours with a murderer, and what they said to each other will never be known.
Past Offences by Rich Westwood is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.