‘When I started as an under-keeper my boss used phosdrin – mostly against rats – but I’ve not seen it on the estate for years.’

‘You had some?’ George said. ‘Was it kept in a jar?’

‘Aye. Once upon a time. But I’ve told you I’ve not seen it for ages.’

‘You’ve never thrown it away?’

‘No,’ he said. ‘ I’ve never thrown it away.’

‘So the jar should still be here,’ George said cheerfully. He went into the shed, crouching to get in through the low door. Although he had seen pole traps and snares before, the rusting metal objects still offended him. But Liddle had been telling the truth when he said they had not been recently used. They were covered in dust and cobwebs. He clambered over them, ignoring Marie’s protests that he would get his clothes dirty, to the shelf at the back of the outhouse.

‘I wonder,’ he said, ‘if I might borrow a torch.’

‘There’s one in the kitchen,’ Marie said quickly. ‘I’ll get it.’

‘What are you, then?’ Vic demanded, the hostility returning with his wife’s absence. ‘Some sort of conservationist?’

‘Something like that.’

‘Keepers care about the countryside too,’ he said. ‘We’re not all monsters.’

‘No,’ George said. ‘Of course not.’

Marie came back with the torch.

‘If I shine it for you,’ she said, ‘you’ll be able to use both hands.’ She had begun to quite enjoy the adventure of Palmer-Jones’s visit. It distracted her from her other worries. She looked out of place, rather comical, perched at the door of the outhouse. Vic crouched to stroke the dog’s nose and pretended to have no interest in what was going on.

At first George just stood and looked. There were coloured bottles and rusting tins. The shelf and all the bottles seemed covered with dust. Then George saw a jam jar with a screw lid, tucked at the back behind a tin of wood preservative. The dust on the jar had been disturbed around the neck, and a ring in the dust on the shelf showed where it had been removed and replaced. George took a large handkerchief from his jacket pocket and lifted the jar by the screw top. He carried it out into the sunlight. In spidery writing on a paper label was written phosdrin. The jar was empty.

Vic and Marie stared at it. Neither spoke.

‘I don’t suppose you remember,’ George said, ‘ if there was any left when you saw it last.’

‘Of course not,’ Vic said violently. ‘ How would we see it, hidden away there?’

‘Yes,’ George said. ‘Quite.’ Then, absentmindedly: ‘You won’t mind if I take this away with me? I’d like to get it analysed.’

‘I suppose not,’ Vic said, ‘ though you seem to be taking rather a lot on yourself. I don’t know what Mr Grenville would say.’