Clearly such a blow must have been struck from behind. That was to some extent in favour of the accused, as when seen quarrelling he was face to face with his father. Still, it did not go for very much, for the older man might have turned his back before the blow fell. Still, it might be worth while to call Holmes’ attention to it. Then there was the peculiar dying reference to a rat. What could that mean? It could not be delirium. A man dying from a sudden blow does not commonly become delirious. No, it was more likely to be an attempt to explain how he met his fate. But what could it indicate? I cudgelled my brains to find some possible explanation. And then the incident of the grey cloth seen by young McCarthy. If that were true the murderer must have dropped some part of his dress, presumably his overcoat, in his flight, and must have had the hardihood to return and to carry it away at the instant when the son was kneeling with his back turned not a dozen paces off. What a tissue of mysteries and improbabilities the whole thing was! I did not wonder at Lestrade’s opinion, and yet I had so much faith in Sherlock Holmes’ insight that I could not lose hope as long as every fresh fact seemed to strengthen his conviction of young McCarthy’s innocence.