‘I believe, Watson, that Atalanta Wyndham was incarcerated in an asylum at the time of her sister’s murder,’ said Holmes quietly.

Hadley cleared his throat. ‘Er, no. She escaped almost immediately and returned home.’

Holmes stood still for a good five seconds. Once again, the tumblers were turning.

‘Father Lamb, had Atalanta Wyndham approached Mr Buttons for counselling?’ he asked.

‘She had. But he discerned that she was merely spying on her sister. He was kind but gave her no information.’

Holmes laughed suddenly, with that strange enthusiasm which made him so odd at times like this. ‘Yes! Of course! Thank you, Mr Hadley,’ he shouted. ‘Of course! Atalanta’s escape clears up one final mystery. What a puzzle. What a glorious puzzle! Ha ha!’

Electrified by whatever this news meant to him, he strode to the door and knocked on it four times for emphasis as he said, ‘One. Two. Three. Four. Atalanta! Peregrine! Leo! Freddie! So many tangled in this web. All with reasons to hate Miss Wyndham! And yet … still, I say, she was killed for love.’

His eyes shone and he looked, quite frankly, mad. I had noted these oddly theatrical performances on several occasions. He was truly pushing the boundaries with this one. ‘Holmes—’ I murmured.

‘Love! When a murder is committed for love, it is the ultimate paradox! But what a capricious if not occasionally downright cruel young woman Miss Dillie Wyndham was!’ he said.

‘Well, the woman brought disaster upon herself,’ said Father Lamb. ‘It was as though she asked to be murdered.’ He paused. ‘God rest her soul,’ he added.

Holmes made an immediate left turn. His manner abruptly turned sober; his voice became very quiet. ‘Father, no one asks to be murdered. The poor girl was sorely used. Her private life was a misery.’ He advanced on the priest and stood directly facing the seated man. ‘Dillie confessed all of this to Peregrine Buttons. He offered her friendship. Kindness. Understanding. Her life at home was nothing short of a nightmare.’

‘Oh, come now, Mr Holmes,’ interrupted Inspector Hadley. ‘Professor Wyndham is a respected man. He is known to be just … rather strict.’

‘It is worse than that, Mr Hadley,’ said Holmes. ‘Wyndham is a cruel abuser, keeping the three women of his family in torment. Dillie responded by emulating him. And yet I had hope for her. Many children manage to recover from cruel treatment and turn the other way.’

This was not the first time that Holmes made me wonder about his own childhood.

‘But Dillie did not get the chance,’ he continued. ‘Atalanta escaped, you say? It was she, then, at the Jesus Lock, opening the drain as we tried to save Buttons. Intending to kill Buttons, I suspect. My death would have merely been a bonus.’