‘If she struck the face of her murderer with the force this indicates, there would surely be a mark on him,’ said Hadley, who had been watching with interest. ‘Or her, if the murderer were female,’ said I. ‘But I rather think a larger person, so more likely a man. Her left fourth finger was bare, with an abrasion near the second joint. Had a ring been torn from her hand? And yet this wound looks slightly less fresh.’

‘Ah,’ said Caswell, ‘I missed that.’ He looked closer. ‘As to the timing of this injury, the immersion makes this uncertain.’

‘By the amount of liquid in the lungs, Miss Wyndham was alive and breathing when she hit the water,’ I said. Her hair was tangled, more so than one might have predicted. A small patch of hair was torn free, the scalp had bled, but very little. Torn off in the lock, no doubt.

‘Oh, to be trapped in the lock like that,’ said Hadley, shaking his head. The senior man had more feeling than I had credited.

Unbidden, a sudden image washed across my mind, another woman, perhaps thirty, floating in water, tangled in some branches, the river rushing past her. A flash and then an image of a six-year-old girl, her body floating underwater and undulating with a strong current.

A wave of sadness flooded me. I closed my eyes for a moment, shaking my head to dispel the vivid thought.

I focused again on the body of Odelia Wyndham. Evidence of a severe blow to the forehead, and gentle palpating revealing a shattered skull, divulged the coup de grace. ‘From this head injury, I believe she was knocked unconscious before hitting the water. She would have died soon after from bleeding in the brain, but it is likely that she did not suffer in the drowning.’

‘A small blessing,’ murmured Hadley.

Holmes would have the entire picture of the struggle in his head, no doubt, and minutes before our own conclusions.

I then asked to see the items of clothing in which she’d been found.

‘There were none,’ said Hadley.

‘No clothing?’ I cried, aghast that this fact had not been mentioned to me earlier. But of course, it was why they would not let me examine her in situ at the river. That Odelia Wyndham fell or was thrown naked into the lock put an entirely different light on events.

‘We did not wish for this fact to receive public attention,’ said Hadley, ‘given the prominence of the family. My men have been sworn to secrecy.’

‘Who found the body?’

‘A baker en route to his shop at five in the morning.’

‘But that was hours ago!’