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 round 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, walking 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 and far above that, 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 The head was withdrawn.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.