Grant explained that even in this, the most recent of the three levels of San Tommaso, there was a great richness of time sequences. When in the twelfth century the ancient church below it was filled in, its treasures, including pieces from the pagan household underneath it, were brought up into this new basilica so that now classical, medieval and renaissance works mingled. ‘They’ve kept company,’ Grant said, ‘for a long time and have grown together in the process. You can see how well they suit each other.’

‘It happens on the domestic level too,’ Alleyn said, ‘don’t you think? In houses that have belonged to the same family for many generations? There’s a sort of consonance of differences.’

‘Exactly so,’ Grant agreed with a quick look at him. ‘Shall we move on?’

A wave of scent announced the arrival of Lady Braceley at Alleyn’s elbow. ‘What a marvellous way of putting it,’ she murmured. ‘How clever you are.’

The doeskin glove with its skeletal enclosure touched his arm. She tipped her head on one side and was looking up at him. Sophy, watching, thought a shutter had come down over his face and indeed Alleyn suffered a wave of revulsion and pity and a recognition of despair. I’d give a hell of a lot, he thought, to be shot of this lady.

Sebastian Mailer had come up on the far side of Lady Braceley. He murmured something that Alleyn couldn’t catch. Grant was talking again. The hand was withdrawn from Alleyn’s arm and the pair turned away and moved out of sight behind the junction of two pilasters. Now, Alleyn speculated, was Mailer doing a rescue job or had he something particular and confidential to say to Lady Braceley?

Grant led his party into the centre of the nave and through the enclosed schola cantorum, saying, Sophy thought, neither too much nor too little but everything well. She herself was caught up in wonder at the great golden bowl-shaped mosaic of the apse. Acanthus and vine twined tenderly together to enclose little groups of everyday persons going about their medieval business. The Cross, dominant though it was, seemed to have grown out of some pre-Christian tree. ‘I shall say nothing about the apse,’ Grant said. ‘It speaks for itself.’

Mailer and Lady Braceley had re-appeared. She sat down on a choir bench and whether by some accident of lighting or because she was overtaken by one of those waves of exhaustion that unexpectedly fall upon the old, she looked as if she had shrunk within her own precarious façade. Only for a moment, however. She straightened her back and beckoned her nephew who fidgeted about on the edge of the group, half-attentive and half-impatient. He joined her and they whispered together, he yawning and fidgeting, she apparently in some agitation.