“Well, I’ll break my rule and indulge in a bit of speculation on my own account. It occurs to me there is another possible explanation for their double disappearance.”

“Indeed? Please tell me of it.”

Alleyn did so. Valdarno stared straight in front of him and nursed his splendid moustache. When Alleyn had finished, he turned an incredulous gaze upon him and then decided to be arch. He shook his finger at Alleyn. “Ah-ah-ah, you pull my leg,” he said.

“I don’t, you know.”

“No? Well,” said the Questore, thinking it over, “we shall see. Yet I fear,” he added, giving Alleyn a comradely clap on the shoulder, “that we shall see — nothing in particular.”

They moved laboriously onwards and down. To the church on the second level. To the first smiling Apollo and the tall woman with the broken child, to the white Apollo with a crown of leaves, to the Mercury behind whom Baron Van der Veghel had so playfully hidden.

The men flashed torchlights into the recesses and niches. Alleyn looked into them a little more closely. Behind the white Apollo he found a screwed-up piece of glossy blue paper which he retrieved and wrapped in his handkerchief, sharply observed by Valdarno, to whom he scrupulously confided his reasons for doing so. Behind the Mercury he found a sealing tab from an undeveloped film, left there no doubt by Baron Van der Veghel when he played his little joke and frightened Lady Braceley into fits.

On to the railed hole in the floor of the second level cloister, where Baroness Van der Veghel had peered into the underworld and where Sophy Jason and Alleyn, also looking down, had seen the shadow of a woman they took to be Violetta.

Alleyn reminded Valdarno of this and invited him to stand where Sophy had stood while he himself looked over the Questore’s shoulder. There was no lighting down below and they stared into a void.

“You see, Signor Questore, we are looking straight down into the well-head on the bottom level. And there to the right is the end of the sarcophagus with the carved lid. You can, I think, just make it out. I wonder — could one of your men go down there and switch on the normal lighting. Or perhaps—” He turned with diffidence to the Dominican. “I wonder,” he said, “if you would mind going down, Brother Dominic? Would you? You are familiar with the switches and we are not. If we could just have the same lighting as there was yesterday? And if you would be very kind and move between the source of light and the well, we’d be most grateful.”

Brother Dominic waited for so long, staring in front of him, that Alleyn began to wonder if he had taken some vow of silence. However, he suddenly said, “I will,” in a loud voice.

“That’s very kind of you. And — I hope I’m not asking for something that is not permitted — would you have your hood over your head?”

“What for would I be doin’ that?” asked Brother Dominic in a sudden access of communication.

“It’s just to lend a touch of verisimilitude,” Alleyn began and to his astonishment Brother Dominic instantly replied: “ ‘To an otherwise bald and unconvincing narrative’?”

“Bless you, Brother Dominic — You’ll do it?”

“I will,” Brother Dominic repeated and stalked off.

“These holy fathers!” Valdarno tolerantly observed. “The one talks to distraction and the other has half-a-tongue. What is it you wish to demonstrate?”

“Only, in some sort, how the shadow appeared to us.”

“Ah, the shadow. You insist on the shadow?”

“Humour me.”

“My dear colleague, why else am I here? I am all attention.”

So they leant over the railing, stared into the depths and became aware of the now familiar burble of subterranean water.

“Almost,” Alleyn said, “you can persuade yourself that you see a glint of it in the well — almost but not quite. Yesterday I really thought I did.”

“Some trick of the light.”

“I suppose so. And pat on his cue, there goes Brother Dominic.”

A concealed lamp had been switched on. The lid of the sarcophagus, the wall behind it and the railings round the well all sprang into existence. Their view from immediately above was one of bizarre shadows and ambiguous shapes, of exaggerated perspectives and detail. It might have been an illustration from some Victorian thriller: a story of Mystery and Imagination.

As if to underline this suggestion of the macabre a new shadow moved into the picture: that of a hooded form. It fell across the sarcophagus, mounted the wall, grew gigantic and vanished.

“Distorted,” Alleyn said, “grotesque, even, but quite sharply defined, wasn’t it? Unmistakably a monk? One could even see that the hands were concealed in the sleeves. Brother Dominic obliging in fact. The shadow Miss Jason and I saw yesterday was equally well defined. One saw that the left shoulder was markedly higher than the right, that the figure was a woman’s and even that she carried some tray-like object slung around her neck. It was, I am persuaded, Signor Questore, the shadow of Violetta and her postcards.”

“Well, my friend, I do not argue with you. I will take it as a working hypothesis that Violetta escaped the vigilance of the good fathers and came down here. Why? Perhaps with the intention of pursuing her quarrel with Mailer. Perhaps and perhaps. Perhaps,” the Questore continued with a sardonic inflection, “she frightened him and that is why he ran away. Or even — as you have hinted — but come — shall we continue?”

Alleyn leant over the well rails and called out. “Thank you, Brother Dominic. That was excellent. We are coming down.”

He had a resonant voice and it roused a concourse of echoes: “—down — ow — ow — ow — n—n.”

They descended the circular iron stairway, walked along the narrow passage and found Brother Dominic, motionless beside the well-head. The scene was lit as it had been yesterday afternoon.

Alleyn stood by the well-head and looked up. The opening above his head showed as a brilliant square of light. Far above that, was the opening into the basilica. As he watched, Father Denys’s head appeared at the top level, peering into the depths. If Father Denys, like Violetta, was given to spitting, Alleyn thought, he would spit straight in my eye.

“Are you all right, beneath?” asked Father Denys and his voice seemed to come from nowhere in particular.

“We are,” boomed Brother Dominic without moving. The head was withdrawn.

“Before we turn on the fluorescent light,” Alleyn said, “shall we check on the movements of the woman in the shawl. Brother Dominic, I take it that just now you walked from the foot of the iron stair where you turned on the usual lighting, down the passage and across the light itself to where you now stand?”

“I did,” said Brother Dominic.

“And so must she, one would think?”

“Of course,” said Valdarno.

“It wasn’t quite the same, though. Violetta’s shadow — we are accepting Violetta as a working hypothesis — came from the right as Brother Dominic’s did and, like his, crossed to the left. But there was a sequel. It re-appeared, darting into view, lying across the sarcophagus and up the wall. It paused. It turned this way and that and then shot off to the right. The suggestion, a vivid one, was of a furtive person looking for a hiding place. Miss Jason thought so, too.”

“Did Mailer comment?”

“He pooh-poohed the idea of it being Violetta and changed the subject.” Alleyn looked about him. “If we extend the ‘working hypothesis’ which, by the way, Signor Questore, is a nice alternative to the hateful word ‘conjecture,’ we must allow that there are plenty of places where she could hide. Look what a black shadow the sarcophagus throws, for instance.”

Alleyn had a torch and now used it. He flashed it along the well rails, which turned out to be makeshift constructions of roughly finished wood.

“You would like the working lights, Signore?” said one of the men.