‘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.’

‘I wonder,’ murmured Troy.

‘And so, you may depend upon it, do I. There’s one other point which has been kindly elucidated by the gibbering Dimitri. This morning he sent his servant out for a Times. When we heard of this we had a look at The Times, too. We found the agony-column notice that I talked about when poor Mildred was trying not to go to sleep, and before I could tell you how much I approve of the solemn way you knit your brows when you listen to me. Now, this notice read like this: “Childie Darling. Living in exile. Longing. Only want Daughter. Daddy.” A rum affair, we thought, and we noticed in our brilliant way that the initial letters read “C.D. Lie low. D.D.” which might not be too fancifully elaborated into “Colombo Dimitri, lie low, Daniel Davidson.” And, in fact, Mr Dimitri confessed to this artless device. It was arranged, he says, that if anything unprecedented, untoward, unanticipated, ever occurred, Davidson would communicate with Dimitri in precisely this manner. It was a poor effort, but Sir Daniel hadn’t much time. He must have composed it as soon as he got home after his night’s work. Anything more?’

‘What about Dimitri and Withers?’