The two policemen finished writing down her statement and offered it to her to sign. They were shown out and made their way back over the weir and the rickety metal walkway across the lock gates to the southern bank. Once they were solidly on dry land, Wickens turned to Cottesloe and said: ‘Did you see her arms?’ Seeing his colleague shake his head, he continued: ‘They were criss-crossed by scars, lots and lots of old scars. Self-harm. I think there’s evidence of mental health.’

‘Interesting,’ Cottesloe said. ‘Did you see the date of birth on her statement?’

‘No.’

‘Born in 1938. Eighty-one years old. I’d reckoned sixty-five.’

‘No way! And she still wanted you in her bedroom.’ Wickens nudged him in the ribs.

‘You, young man, have a one-track mind. She clearly loves living here, and I can see why. It’s beautiful, which is why painters like Sisley were drawn to it.’

‘So what about the car that was drawn to it? Making all that racket on the bridge.’

‘Probably nothing. If you’re going to dump a body in the water, it sounds stupid to draw attention to yourself.’

‘Double bluff,’ Wickens said. ‘That’s just what they want us to think.’

Cottesloe grinned at his colleague’s easy certainties. ‘Let’s see if any of the other witnesses can fill in the blanks.’

Cottesloe and Wickens finally had something to get their teeth into. Elvira Hart’s report about a party led them back to Tagg’s Island. It was eleven a.m. The Drifter was a large, white two-storey clinker-built houseboat moored on the island, right by the southern edge of the bridge. As the two officers boarded the large exterior deck, they took in the smoked-glass picture window over the water and the roof terrace filled with pot plants and strung with decorative lamps. The door was answered by a slim blue-eyed man in his sixties, face screwed up against the light. ‘Yeah?’ He looked horribly hung-over.

He had a ponytail of iron-grey hair and was wearing a leather waistcoat over a partially unbuttoned white shirt. Tight black jeans, no shoes and a large mug of black coffee in his hand. Behind him, a thirtyish woman with bed-hair of tabby shades and a resentful expression tightened the belt on her thigh-length white kimono.

While Cottesloe made the introductions, Wickens’ eye strayed to the woman. She had long tanned legs and shapely feet with red varnished toenails. The rustle of silk as she showed them in enticed him to imagine her naked.

‘We’ve come to take a full statement from you both about last night,’ Cottesloe said.

‘What about last night?’

‘The body that was discovered this morning just downstream.’