The House Of Silk

it, you would inherit everything that had been his. This house, the money, the art … all of it would be yours. It is hard to imagine the hatred that must have been driving you forward, the relish with which you went about your task.’
    ‘It has been a pleasure, Mr Holmes. I have enjoyed every minute of it.’
    ‘My mother?’ Carstairs gasped the two words.
    ‘The most likely explanation was the one you first suggested to me, that the gas fire in her bedroom blew out. But it was not one that stood up to scrutiny. For your manservant, Kirby, told us that he blamed himself for the death as he had stopped up every crack and crevice in the room. Your mother disliked draughts so it was impossible that a draught could have blown out the fire. Your sister, however, had come to another conclusion. She believed that the late Mrs Carstairs had taken her own life, so distraught was she at your marriage. But as much as Eliza loathed your new wife and instinctively knew her to be dissembling, even she was unable to arrive at the truth, which is that Catherine Carstairs entered the room and deliberately blew out the flame, leaving the old lady to perish. There could be no survivors, you see. For the property to be hers, everyone had to die.’
    ‘And Eliza?’
    ‘Your sister is being slowly poisoned.’
    ‘But that’s impossible, Mr Holmes. I told you—’
    ‘You told me that you have carefully examined everything she has eaten, which only suggests to me that she is being poisoned in another way. The answer, Mr Carstairs, is the bath. Your sister insists on bathing regularly and uses strong, lavender bath salts. I must confess that this is a most novel way of administering poison, and I am frankly surprised that it has been so effective, but I would say that a small measure of aconitine has been added, regularly, to the bath salts. It has entered Miss Carstairs’s system through her skin and also, I would imagine, through the moisture and the fumes which she has, of necessity, absorbed. Aconitine is a highly toxic alkaloid which is soluable in water and which would have killed your sister instantly if a large dose had been used. Instead, you have noted this slow but remorseless decline. It is a striking and innovative method of murder, Mrs Carstairs, and one which I am sure will be added to the annals of crime. It was also quite daring of you, incidentally, to visit my colleague while I was incarcerated, although you naturally pretended you knew nothing of that. It doubtless persuaded your husband of your devotion to your sister-in-law while, in fact, you were actually laughing at them both.’
    ‘You devil!’ Carstairs twisted away from her in horror. ‘How could you? How could anyone?’
    ‘Mr Holmes is right, Edmund,’ his wife returned and I noticed that her voice had changed. It was harder, the Irish accent now prominent. ‘I would have put all of you in your graves. First your mother. Then Eliza. And you have no idea what I was planning for you!’ She turned to Holmes. ‘And what now, clever Mr Holmes? Do you have a policeman waiting outside? Should I go upstairs and pack a few things?’
    ‘There is indeed a policeman waiting, Mrs Carstairs. But I have not finished yet.’ Holmes drew himself up and I saw a coldness and a vengefulness in his eyes that went beyond anything I had ever seen before. He was a judge about to deliver sentence, an executioner opening the trapdoor. A certain chill had entered the room. A month from now, Ridgeway Hall would be empty, unoccupied – and am I too fanciful to suggest that something of its fate was already being whispered, that somehow the house already knew? ‘There is still the death of the child, Ross, to be accounted for.’
    Mrs Carstairs burst out laughing. ‘I know nothing about Ross,’ she said. ‘You have been very bright, Mr Holmes. But now you go beyond yourself.’
    ‘It is no longer you I am addressing, Mrs Carstairs,’ Holmes replied and turned instead to her husband. ‘My investigation into your affairs took an unexpected turn on the night that Ross was murdered, Mr Carstairs, and that is not a word I use often, for it is my habit to expect everything. Every crime that I have ever investigated has had what you might call a narrative flow – it is this invisible thread that my friend, Dr Watson, has always unerringly identified. It is what has made him such an excellent chronicler of my work. But I have been aware that this time I have been