‘A grey cat?’ I asked slowly.

‘Yes, sir. A Persian.’

‘And you say it was destroyed?’

‘Yes, sir.’

‘You’re quite sure it was destroyed?’

‘Oh! quite sure, sir. Her ladyship wouldn’t have him sent to the vet—but did it herself. A little less than a week ago now. He’s buried out there under the copper beech, sir.’ And he went out of the room, leaving me to my meditations.

Why had Lady Carmichael affirmed so positively that she had never had a cat?

I felt an intuition that this trifling affair of the cat was in some way significant. I found Settle and took him aside.

‘Settle,’ I said. ‘I want to ask you a question. Have you, or have you not, both seen and heard a cat in this house?’

He did not seem surprised at the question. Rather did he seem to have been expecting it.

‘I’ve heard it,’ he said. ‘I’ve not seen it.’

‘But that first day,’ I cried. ‘On the lawn with Miss Patterson!’

He looked at me very steadily.

‘I saw Miss Patterson walking across the lawn. Nothing else.’

I began to understand. ‘Then,’ I said, ‘the cat—?’

He nodded.

‘I wanted to see if you—unprejudiced—would hear what we all hear . . . ?

‘You all hear it then?’

He nodded again.

‘It’s strange,’ I murmured thoughtfully. ‘I never heard of a cat haunting a place before.’

I told him what I had learnt from the footman, and he expressed surprise.

‘That’s news to me. I didn’t know that.’

‘But what does it mean?’ I asked helplessly.

He shook his head. ‘Heaven only knows! But I’ll tell you, Carstairs—I’m afraid. The—thing’s voice sounds—menacing.’

‘Menacing?’ I said sharply. ‘To whom?’

He spread out his hands. ‘I can’t say.’

It was not till that evening after dinner that I realized the meaning of his words. We were sitting in the green drawing-room, as on the night of my arrival, when it came—the loud insistent miaowing of a cat outside the door. But this time it was unmistakably angry in its tone—a fierce cat yowl, long-drawn and menacing. And then as it ceased the brass hook outside the door was rattled violently as by a cat’s paw.

Settle started up.

‘I swear that’s real,’ he cried.

He rushed to the door and flung it open.

There was nothing there.

He came back mopping his brow. Phyllis was pale and trembling, Lady Carmichael deathly white. Only Arthur, squatting contentedly like a child, his head against his stepmother’s knee, was calm and undisturbed.

Miss Patterson laid her hand on my arm as we went upstairs.

‘Oh! Dr Carstairs,’ she cried. ‘What is it? What does it all mean?’

‘We don’t know yet, my dear young lady,’ I said. ‘But I mean to find out. But you mustn’t be afraid. I am convinced there is no danger to you personally.’

She looked at me doubtfully. ‘You think that?’

‘I am sure of it,’ I answered firmly. I remembered the loving way the grey cat had twined itself round her feet, and I had no misgivings. The menace was not for her.