‘I don’t believe in all these drugs,’ said Miss Russell, her eyes sweeping over my array of bottles disparagingly. ‘drugs do a lot of harm. Look at the cocaine habit.’

‘Well, as far as that goes-’

‘It’s very prevalent in high society.’

I’m sure Miss Russell knows far more about high society than I do. I didn’t attempt to argue with her.

‘Just tell me this, doctor,’ said Miss Russell. ‘Suppose you are really a slave of the drug habit, is there any cure?’

One cannot answer a question like that off-hand. I gave her a short lecture on the subject, and she listened with close attention. I still suspected her of seeking information about Mrs Ferrars.

‘Now, veronal, for instance-’ I proceeded.

But, strangely enough, she didn’t seem interested in veronal. Instead she changed the subject, and asked me if it was true that there were certain poisons so rare as to baffle detection.

‘Ah!’ I said. ‘you’ve been reading detective stories.’

She admitted that she had.

‘The essence of a detective story,’ I said, ‘is to have a rare poison – if possible something from South America, that nobody has ever heard of – something that one obscure tribe of savages use to poison their arrows with. death is instantaneous, and Western science is powerless to detect it. Is that the kind of thing you mean?’

‘Yes. Is there really such a thing?’

I shook my head regretfully.

‘I’m afraid there isn’t. There’s curare, of course.’

I told her a good deal about curare, but she seemed to have lost interest once more. She asked me if I had any in my poison cupboard, and when I replied in the negative I fancy I fell in her estimation.

I should never have suspected Miss Russell of a fondness for detective stories. It pleases me very much to think of her stepping out of the housekeeper’s room to rebuke a delinquent housemaid, and then returning to a comfortable perusal of The Mystery of the Seventh Death, or something of the kind.

I told Caroline at lunch that I should be dining at Fernly. She expressed no objection – on the contrary.

‘Excellent,’ she said. ‘You’ll hear all about it. By the way, what is the trouble with Ralph?’

‘With Ralph?’ I said, surprised; ‘there isn’t any.’

‘Then why is he staying at the Three Boars instead of at Fernly Park?’

I did not for a minute question Caroline’s statement that Ralph Paton was staying at the local inn. That Caroline said so was enough for me.

‘Ackroyd told me he was in London,’ I said. In the surprise of the moment I departed from my valuable rule of never parting with information.

‘Oh!’ said Caroline. I could see her nose twitching as she worked on this.

‘He arrived at the Three Boars yesterday morning,’ she said. ‘And he’s still there. Last night he was out with a girl.’

That did not surprise me in the least. ralph, I should say, is out with a girl most nights of his life. But I did rather wonder that he chose to indulge in the pastime in king’s Abbot instead of in the gay Metropolis.

‘One of the barmaids?’ I asked.

‘No. That’s just it. he went out to meet her. I don’t know who she is.’ (Bitter for Caroline to have to admit such a thing.) ‘But I can guess,’ continued my indefatigable sister.

I waited patiently.

‘His cousin.’

‘Flora Ackroyd?’ I exclaimed in surprise.

Flora Ackroyd is, of course, no relation whatever really to Ralph Paton but Ralph has been looked upon for so long as practically Ackroyd’s own son, that cousinship is taken for granted.

‘Flora Ackroyd,’ said my sister.