spot at which the tragedy occurred is down a narrow, winding, country lane. While we made our way along it we heard the rattle of a carriage coming towards us, and stood aside to let it pass. As it drove by us I caught a glimpse through the closed window of a horribly contorted, grinning face glaring out at us. Those staring eyes and gnashing teeth flashed past us like a dreadful vision.

‘My brothers!’ cried Mortimer Tregennis, white to the lips. ‘They are taking them to Helston.’

We looked with horror after the black carriage, lumbering upon its way. Then we turned our steps towards this ill-omened house in which they had met their strange fate.

It was a large and bright dwelling, rather a villa than a cottage, with a considerable garden which was already, in that Cornish air, well filled with spring flowers. Towards this garden the window of the sitting- room fronted, and from it, according to Mortimer Tregennis, must have come that thing of evil which had by sheer horror in a single instant blasted their minds. Holmes walked slowly and thoughtfully among the flower-plots and along the path before we entered the porch. So absorbed was he in his thoughts, I remember, that he stumbled over the watering-pot, upset its contents, and deluged both our feet and the garden path. Inside the house we were met by the elderly Cornish housekeeper, Mrs Porter, who, with the aid of a young girl, looked after the wants of the family. She readily answered all Holmes’s questions. She had heard nothing in the night. Her employers had all been in excellent spirits lately, and she had never known them more cheerful and prosperous. She had fainted with horror upon entering the room in the morning and seeing that dreadful company round the table. She had, when she recovered, thrown open the window to let the morning air in, and had run down to the lane, whence she sent a farm-lad for the doctor. The lady was on her bed upstairs, if we cared to see her. It took four strong men to get the brothers into the asylum carriage. She would not herself stay in the house another day, and was starting that very afternoon to rejoin her family at St Ives.

We ascended the stairs and viewed the body. Miss Brenda Tregennis had been a very beautiful girl, though now verging upon middle age. Her dark, clear-cut face was handsome, even in death, but there still lingered upon it something of that convulsion of horror which had been her last human emotion. From her bedroom we descended to the sitting-room where this strange tragedy had actually occurred. The charred ashes of the overnight fire lay in the grate. On the table were the four guttered and burned- out candles, with the cards scattered over its surface. The chairs had been moved back against the walls, but all else was as it had been the night before. Holmes paced with light, swift steps about the room; he sat in the various chairs, drawing them up and reconstructing their positions. He tested how much of the garden was visible; he examined the floor, the ceiling, and the fireplace; but never once did I see that sudden brightening of his eyes and tightening of his lips which would have told me that he saw some gleam of light in this utter darkness.

‘Why a fire?’ he asked once. ‘Had they always a fire in this small room on a spring evening?’

Mortimer Tregennis explained that the night was cold and damp. For that reason, after his arrival, the fire was lit. ‘What are you going to do now, Mr Holmes?’ he asked.

My friend smiled and laid his hand upon my arm. ‘I think, Watson, that I shall resume that course of tobacco-poisoning which you have so often and so justly condemned,’ said he. ‘With your permission, gentlemen, we will now return to our cottage, for I am not aware that any new factor is likely to come to our notice here. I will turn the facts over in my mind, Mr Tregennis, and should anything occur to me I will certainly communicate with you and the vicar. In the meantime I wish you both good morning.’

It was not until long after we were back in Poldhu Cottage that Holmes broke his complete and absorbed silence. He sat coiled in his armchair, his haggard and ascetic face hardly visible amid the blue swirl of his tobacco smoke, his black brows drawn down, his forehead contracted, his eyes vacant and far away. Finally, he laid down his pipe and sprang to his feet.