‘No,’ George said. ‘I really don’t think so. Marcus Grenville is an ambitious man and he wants high office. His only hope is to get into government through his environmental interest. If it became public knowledge that he wasn’t as clean – or as green – as his PR people would like us all to believe, he would lose his last chance. I don’t believe he’d be prepared to take the risk.’

The phone rang on Benwell’s desk and there was a short and incomprehensible conversation. The policeman replaced the receiver then looked at George, expecting him to continue.

‘I’ve been thinking,’ George said, ‘that there might still be poisoned bait on the hill. It might be worth a look.’

‘Would you be able to do that?’ Benwell said. ‘A stroll on the hill behind Back Rigg shouldn’t attract too much attention. Not if you’re staying in the house.’

‘Of course I could do it,’ George said, ‘if you want me involved. I thought you might prefer me to keep out of your way. I’ve not official standing any more.’

There was another pause. Somewhere in the building a door banged shut. The room was very hot. Benwell chose his words carefully. He wanted to make his position quite clear.

‘Look,’ he said. ‘You might be right about Mrs Ottway but at the moment the whole thing is too … politically sensitive for me to wade in without proper proof. As you say, the rumour could easily wreck Marcus Grenville’s career. I’ve got to wait for the post-mortem results before I take any action. You do see that?’

George nodded. He was disappointed but he had already achieved more than he had expected.

‘But you’re not working under the same constraints,’ Benwell went on. ‘You’ve been employed by Grenville, given permission to investigate the poisoning incidents. I know of your reputation – we all read your papers on interviewing techniques during training – and if you can dig up any information before I can begin the formal investigation I’d be grateful.’ He hesitated again. ‘But perhaps you have other commitments,’ he said. ‘Perhaps you feel you deserve some peace in your retirement.’

‘No,’ said George. He felt absurdly flattered. ‘No. I’ll be pleased to help.’

‘Had you intended to stay at the farm for a while anyway?’

‘Yes,’ George said. ‘At least until after the funeral. There’s a daughter but she wants to leave the arrangements to us.’

‘She couldn’t have had anything to do with this business?’

‘No,’ George said. ‘I hardly think so.’