Tanika swiped the screen a few times until an image appeared. It was of Liz Curtis lying on the grass, her limbs splayed like a rag doll’s, her face a shocking mess of red blood.

In the centre of her forehead there was a bullet hole.

‘It’s Liz Curtis,’ Judith said, resisting her instinct to look away.

‘Thank you.’

‘Any signs of a struggle?’

Tanika didn’t answer, but Judith correctly interpreted her silence as assent.

‘And she was found by a scoutmaster?’

‘That’s right. He and his scouts hired kayaks from Liz this morning and went out on the river at about nine.’

‘So she was alive at nine o’clock?’

‘Very much so. She did the safety briefing for everyone. Anyway, the scouts were out on the river about an hour and returned to the rowing centre shortly after ten. That’s when the scoutmaster found her body. Fortunately, he was able to stop the children from approaching, rounded them up and got them back into Marlow. I’ve a constable taking his statement now.’

‘That’s a very clear time of death. Between nine-ish and ten-ish this morning. Have you checked up on Elliot Howard?’

‘I’ll be honest, it was the first thing I did. He’s been running an auction since eight thirty this morning.’

‘He has?’

‘And it’s all being filmed on a livestream for the internet.’

‘You’re kidding me!’

‘I know.’

‘But why would an auction start at eight thirty?’

‘Apparently it’s for the overseas buyers. But he’s in the clear. He’s got witnesses all around the world who can alibi him for between nine and ten this morning.’

‘Hmm,’ Judith said, deeply frustrated. She was sure that Elliot was behind Stefan’s murder. In fact, the theory that had been bubbling away on the back burner for her had been the idea that Liz had maybe killed Stefan on Elliot’s behalf, for some reason yet to be established. And Elliot had now killed Liz, so there’d never be a chance for anyone to pin the first murder on him. But her theory fell apart if Elliot had an alibi for the time of Liz’s murder.

Judith realised there was a question she’d not asked yet.

‘You said her husband was in Nottingham?’

‘You think he might be involved?’

‘It would be nice if one of these murders was carried out by someone obvious.’

‘I know. But between the hours of nine and ten this morning, Danny Curtis was having breakfast at a service station by junction twenty-five of the M1. He was at the National Watersports Centre last night.’

‘He has an alibi for this morning?’

‘He was over a hundred miles away at the time.’

‘Are you certain?’

‘A uniformed officer picked Mr Curtis up from outside Nottingham at ten thirty this morning. Whoever did this was in Marlow this morning.’