‘Please tell me the end of the case.’

‘I would rather tell you that since this afternoon in the few spare moments I have had to spend upon it I have considered your case and that I have decided to take out a warrant for your arrest. The charge is impeding an officer of the law in the execution of his duty.’

‘Don’t be so damned facetious,’ said Troy.

‘All right. Where was I?’

‘You had got to the third point against Davidson.’

‘Yes. The third point was in the method used in committing the crime. I don’t think Bunchy would mind if he knew that even while I described his poor little body I was thinking of the woman to whom I spoke. Do you? He was such an understanding person, wasn’t he, with just the right salty flavour of irony? I’m sure he knew how short-lived the first pang of sorrow really is if only people would confess as much. Well, Troy, the man who killed him knew how easy it was to asphyxiate people and I didn’t think many killers would know that. The only real mark of violence was the scar made by the cigarette-case. A doctor would realize how little force was needed and Bunchy’s doctor would know how great an ally that weak heart would be. Davidson told me about the condition of the heart because he knew I would discover he had examined Bunchy. He kept his head marvellously when I interviewed him, did Sir Daniel. He’s as clever as paint. We’re searching his house tonight. Fox is there now. I don’t think we’ll find anything except perhaps the lethal cigarette-case, but I’ve more hopes of Dimitri’s desk. I couldn’t get into that yesterday.’

‘What about the cloak and hat?’

‘That brings us to a very curious episode. We have searched for the cloak and hat ever since four o’clock yesterday morning and we have not found them. We did our usual routine stuff, going round all the dust-bin experts and so on and we also notified the parcels-post offices. This afternoon we heard of a parcel that had been dumped at the Main Western office during the rush hour yesterday. It was over-stamped with tuppenny stamps and addressed to somewhere in China. The writing was script which was our blackmailer’s favourite medium of expression. It’s gone, alas, but I think there’s just a chance we may trace it. It’s a very long chance. Now who is likely to have an unlimited supply of tuppenny stamps, my girl?’

‘Somebody who gives receipts?’

‘Bless me, if you’re not a clever old thing. Right as usual, said the Duchess. And who should give receipts but Sir Daniel, the fashionable physician? Who but he?’

‘Dimitri for one.’

‘I’m sorry to say that is perfectly true, darling. But when I was in Davidson’s waiting-room, I saw several of those things that I think are called illustrated brochures. They appealed for old clothes for the Central Chinese Medical Mission at God knows where. It is our purpose, my dear Troy, to get one of those brochures and write to the Central Chinese Mission asking for further information.’