“The case was clinched,” Alleyn wrote, “when I saw young Dorne’s snapshot. No Baron.

“It’d been a possibility all along. While we were lined up in that preposterous group scarcely able to see each other he hadn’t spoken. She talked to him. When she told him to stand further back and not to speak he wasn’t there. While she fussed about hunting for her second flashlamp — and of course the first dud was a put-up affair — he was off by the passage behind that smirking little god. He had his date with Mailer. He had to hand over the money. Mailer was to dispose of it — in the car I expect — and had stayed behind for that purpose.

“At the moment when we all heard Violetta’s voice, Van der Veghel was in the passage. I don’t believe he witnessed the murder. I think he came upon Mailer with Violetta dead at his feet. I think Mailer bolted and Van der Veghel chased him up the iron stairs to the next landing. There was a struggle. Mailer was knocked out and throttled and tipped over the wellhead. The body fell like a plummet into the well below and in doing so a coat sleeve brushed the inner side of the rail and was torn.

“Van der Veghel climbed the rail at the upper well in order to look down and discover whether his victim had, in fact, made a straight fall into the depths. In doing so the rubber studs on his shoes scored through the brown boot polish that may well have been left there by the abominable Sweet on his way back from dumping Lady B. in the atrium. His brogues were polished underneath the instep, à la the batman he never had. Sweet may have caught sight of Violetta or Mailer or both and snooped.

“My contention is that Van der Veghel, when he looked down, saw that Mailer’s body had gone and that Violetta’s lay where Mailer had left it. He returned and he stowed it in the sarcophagus deliberately leaving a bit of her shawl exposed.

“He wanted Violetta to be found.

“He wanted the police to know Mailer had killed her. He wanted them to believe Mailer had bolted with her death on his head.

“The whole business would, as one says, take less time to happen than it has taken to set it down. Eight minutes at the most, I’d say, and the Baroness was a great deal longer than that, setting up her group, fiddling and faddling, changing her ‘bulps,’ taking a second shot. He was back, on his nimble rubber-studded shoes, well in time to take his own shot of the group. When he removed the film from the Baroness’s camera, he was careful to expose the greater part of it. He didn’t know about young Dorne’s shot.

“And the Baroness? I could have driven him harder here. I could have forced him to confirm what I believe to be her part in the performance. I think she knew they were being blackmailed by Mailer and I think her husband asked her to hold up the proceedings while he kept his assignation and paid over the cash. I don’t believe she knows he killed Mailer and I don’t believe it would make a scrap of difference to their passionate, their overwhelming union if she did.

“And finally — the material for blackmail? Troy, my darling, the chances of distantly related persons bearing a startling physical resemblance to each other are not impossible. But they are extremely remote. In our job we are taught that the ear gives one of the most valuable proofs of identification. The Van der Veghels’ ears are, if not identical, as near as damn it and very, very strange, great ears they are.

“Fox, with his genius for inspiring gossip, has gleaned from a London representative of Adriaan and Welker that the late Baron was what he describes as a bit of a lad with a European reputation as such. The Baroness is said to belong to an expatriate branch of the family. She doesn’t accompany her husband on his visits to The Hague and is understood to be an invalid. She! The Baroness! An invalid!

“I’ve gone on about their strangeness, haven’t I? Their resemblance, not only to each other but to the Etruscan antiquities to which they are so much attracted? I see them as larger than life: classical figures springing about behind, of all things, a non-conformist façade. And I think that very probably they are half-siblings.

“None of this would be provable in a court of law. Even the Baron’s absence from young Dorne’s snapshot could be accounted for. He would say that he had moved out of shot at that juncture and none of us could swear he hadn’t.

“Giovanni? Giovanni had been double-crossed and milched and threatened by the unspeakable Sweet. He was and is greedy to get his own back upon Sweet alive or dead and he grabbed at the chance to concoct his tarradiddle about Sweet’s agitation and suspicious behaviour. The only bit of it that holds up is his account of Sweet standing on the rails at the middle level. Apparently he did just that.

“And the upshot? The Roman police force will present a file in which the available evidence will point to Sweet. I haven’t held anything back from them. I haven’t shoved my own reading of the case under their noses. They are an able body of men and the affair is their affair. I’ve got the information I was sent to get and will be closeted with the Interpol chap tomorrow. Mailer and Sweet were both wanted in England and if they had lived I would have applied for extradition and brought them back.

“I shall always think of the Baron as an antique person in a sudden antique rage, falling upon his enemy like lightning. His consort and his union had been threatened and that was his answer. When in Rome he did as the ancient Romans. I am afraid he does not in the least regret it and I’m afraid I really can’t say that I do.

“The Embassy here has offered to send my report back in the Diplomatic Bag. I’ll enclose this with it. And so, my dear love—”