‘I don’t know.’ The effort of being polite to the Grenvilles had made him uncommunicative. He turned up the track towards the farm.

They saw that there was a light in the house before they noticed the car parked beside the Land Rover. It was faint and Molly decided it was the kitchen light, only visible from the front through an open connecting door.

‘Perhaps it’s Sally,’ she said. ‘ Perhaps she’s found time to come up after all.’ She was pleased by the idea that the woman still had enough affection for her mother to prompt her into making the effort.

But George had recognised the car. ‘No,’ he said. ‘I don’t think it’s Sally. I think it’s the police.’

Dave Benwell was sitting by the kitchen table, reading one of Ursula’s copies of Farmers Weekly. When they came into the room he folded the paper and stood up.

‘The door was open,’ he said. ‘I didn’t think you’d mind me waiting.’ He gave the impression that he would happily have waited all night.

‘No,’ George said. ‘Of course not. Is there any news?’

He found that he was intensely nervous. It was like waiting to hear an exam result. It was a purely selfish anxiety. At that moment he had no thought for Ursula. He was concerned only to find out if his instinct had been right or if he had made some terrible error of judgement.

Benwell returned to his seat. Molly watched him, suspiciously. She knew how vulnerable George was.

‘We had the preliminary report from the pathologist this evening,’ the policeman said. ‘I thought you’d be interested. This is almost on my way home so I called in.’

‘Well?’ George demanded, almost rude in his impatience. ‘Did they find anything?’

‘Phosdrin,’ Benwell said. ‘They found traces of mevinphos in the samples sent to the lab.’

And George could have hugged him.

‘So it was murder,’ he said, giving nothing of his relief away.

‘That’s why I’m here,’ Benwell said, ‘to discuss the alternatives. My boss asked me to come. We have to be sure of our facts, he says, before we make a fuss.’

Molly’s suspicion grew. He’s a coward, she thought. A yes man.

‘Because Marcus Grenville is involved?’ she snapped.

Benwell nodded awkwardly. ‘I suppose there’s not a possibility that it could have been an accident?’ he said. ‘You say this stuff is sometimes injected into hens, eggs. She kept hens, didn’t she? I heard them as I came round the house. Isn’t there a chance that she found eggs on the hill and thought they were safe to eat?’

He looked unhappily at George. Bear with me, he was saying. I have to ask.