‘So he had to put the real painting back. Which is also why he had to have his bonfire. He had to destroy his fake painting along with the real frame and all of his other practice attempts. But it also explains why he was at such a low ebb when Tanika spoke to him over the bonfire. He knew by that point that he’d killed a complete stranger solely so that he could get his father’s Rothko painting back in his hands, and he’d screwed the whole thing up. He’d carried out the murder, but he didn’t have the painting.’

‘And it was you who’d stopped him!’ Suzie said, delighted.

‘Not a bit of it. We all did it together. Now, we’re coming up to a bend in the river, so if I get the line right, we should be able to let the current take us around.’

As Judith said this, she changed the direction of the punt so it headed at ninety degrees from the riverbank. But as the forward momentum of the punt met the stronger current towards the centre of the river, its prow started to turn and Suzie and Becks realised that Judith had set the punt on a course that would allow it to turn with the upcoming bend in the river.

‘You really know what you’re doing,’ Becks said.

‘Oh I wouldn’t say that,’ Judith said as she stowed the punt pole, got out three crystal flutes from her hamper and an unopened pack of strawberries from the local supermarket.

‘Sorry, I meant to prepare the strawberries.’

‘Don’t worry,’ Becks said. ‘I’ll do that.’

‘Let me give you a knife and a plate.’

Judith unclipped a plate and knife from the leather straps inside the hamper and handed them over. She then fished the bottle of champagne out of the ice-cold water of the river and with an expert flick of the wrist, untied the rope one-handed.

‘No, this won’t do,’ Suzie said, undercutting the mood.

The other two women looked at her.

‘I’m sorry,’ she said, looking directly at Judith. ‘But you told me you didn’t know anything about boats.’

‘What’s that?’ Judith asked, not quite following.

‘When I first met you, you said you didn’t know anything about boats. But when I was about to get on this punt this morning you told me I shouldn’t worry because you were an excellent sailor. Those were your exact words.’

‘What’s this?’ Becks asked.

‘You own a punt, for crying out loud. And know how to use the current to get around a bend in the river. And I can’t help noticing, you just untied that knot one-handed.’

‘Your point being?’ Judith said reasonably, but her smile had tightened.

‘That newspaper report we read said that a witness saw two people on your husband’s boat. That second person was you, wasn’t it? Look, we’re friends here, and God knows we’ve been through enough for me to know I can trust the two of you with my life. But put me out of my misery here. Two people went out into that storm that day, but only one of you came back. I’m right, aren’t I?’