‘I don’t know.’ George was shocked, a little disturbed that the detective had pushed the thing to its logical conclusion. ‘I hadn’t gone that far.’ He had a sudden fear that he would provoke a terrible disaster, an unstoppable chain of events. ‘I‘m not making any accusations, you know,’ he said in panic. He thought again that he was a fool, a vacillating old man without the courage of his convictions.

‘If it wasn’t Marcus Grenville,’ Benwell said, ‘who else could it be?’

‘One of the keepers, perhaps. I found the buzzard in Liddle’s shed. It must have been taken from Back Rigg on the night of Ursula’s death, so he’s obviously implicated.’

But I believed him, George thought. I believed his shock and surprise when the buzzard was found.

‘After Grenville the keepers would have the most to lose if Ursula made her allegations public,’ he continued. ‘There’s been a lot of publicity about the use of poison on big estates lately. Grenville would want to dissociate himself with the practice even if he’s turned a blind eye in the past. If one of the keepers was involved he would almost certainly lose his job.’ He paused, uncertain of his ground. ‘Perhaps I shouldn’t have gone to see Liddle this afternoon,’ he said. ‘I didn’t want to pre-empt your investigation, but it seemed important to find out if he had access to phosdrin. The buzzard was a bonus.’

‘And he did have access to the poison?’

‘Apparently. The jar’s empty, but it’s impossible to tell when it was last used. In the past it was put down to kill rats.’

‘Why would anyone want to kill a buzzard?’

George was surprised. He had supposed Benwell was a local man. But perhaps he could only maintain his confident detachment because he was an outsider.

‘Buzzards and other birds of prey are supposed to take young grouse,’ he said, ‘though in fact their impact is nowhere near as great as some keepers seem to think. I suppose it must be annoying if you’ve kept moorland to a high standard and raised a lot of young birds to think that they’re lost to predators. In the past keepers have been put under a lot of pressure by landowners to keep the prey population down. Now that it’s illegal they’re in an impossible situation – if they’re caught using poison they get the sack and if there aren’t as many grouse as expected they’re blamed for not keeping the vermin under control. On lots of estates the message seems to be “do what you have to but make sure you don’t get caught”.’

‘And on the Cadver?’ Benwell asked. ‘ Is that the message there?’