Filippo joined the brethren for the office of Compline in the church, standing where he had a good view of Brancacci's chapel, but it was in darkness, with no candles on the altar. He snuggled into the office of Compline, the scents of wood and wax, the pools of candlelight, the voices of his brethren singing psalms and the rising and falling cadences of the chant.

Hear me when I call, O god of my righteousness: thou hast enlarged me when I was in distress; have mercy upon me, and hear my prayer.

When he had set foot once more on Italian shores he had expected to feel a rush of relief. Yes, he had felt the comfort of language and familiar food, but it was only now, being back in the Carmine at Compline, that he reached the heart, the inner sanctum of home. The changes were disquieting, however. He had walked around the place in the afternoon and discovered that the priest in the confessional no longer smelled of wine, the gap in the monastery wall on the brothel side had been plugged, and that the friars were keeping to their duties rather than to their beds. In his youth, Filippo could stand all day watching Masaccio at work on the walls of Brancacci's chapel with but the mildest rebuff from a passing elder; now, like a creeping fog, a holy fervour was arising in the cloisters.

O ye sons of men, how long will ye turn my glory into shame? How long will ye love vanity, and seek after lies? Selah.

If only he could see Masaccio's frescoes, then his sense of having returned home would be complete.

Stand in awe and sin not: commune with your own heart upon your bed, and be still. Selah.

He looked about at the familiar and unfamiliar faces. There were new novices in the Order, and some of the older friars had passed on. One aged face that he looked on fondly, a long face etched by time, was that of his old master. On the eve of his novitiate, he had been screaming, he remembered, and running round the dormitory squealing like a wild pig, but the master had caught him and taken him to a chapel where they had sat alone together and talked. The master told him what would happen when he took his vows.

'When you become a friar of the Carmelite Order, such is the pleasure of heaven that something very special is granted to you. For every friar of the Order is assured a place in paradise and, on the Saturday following the day of your death, the Virgin Mary herself will come to collect your soul.'

Filippo had stared at his master open-mouthed, for there were implications in this immediately apparent to him. What he wanted to ask was, 'No matter what you've done?' but he restrained himself. The meaning was clear – how could it be clearer? – that just being a Carmelite would absolve him of sin. He had been trying to be good, but then all his intentions began a slow unravelling, for he did not have to struggle any longer. All he had to do, after a year of being a novice, was to take his vows.

Now his old master was gazing at him queerly, as if to see what was written on his soul. Filippo flinched and looked away.

Lord, now lettest thou thy servant depart in peace, according to thy word.

With the closing of the Nunc Dimittis, the friars began to leave the church for their beds. Filippo lingered. He had bathed, had his tonsure renewed and was wearing the dark tunic of the Order with its white mantle and copious hood. This he kept over his head, not wishing to be recognised and caught up by questions about his prolonged absence. Nor did he wish to hear anything further on the cause of all these changes, a new preacher exhorting the brethren to renew their observance of the Rule. Filippo had an innate distrust of such men, especially when he was told that roses poured from his mouth when he preached and angels had been seen holding up his copy of the Gospels.

When the friars had all departed, he took a candle from the altar and went into Brancacci's chapel. It was all so fresh in his memory, the scenes of Saint Peter and the Tribute Money, Saint Peter Preaching, Saint Peter Healing the Sick with his Shadow, Saint Peter raising the son of Theophilius. But, holding up the candle, his jaw dropped. This last scene was of a miracle witnessed by many onlookers, several of whom had been portraits of Brancacci and his friends, but rough-edged holes in the plaster now stood where faces once had been.

At first it looked like an act of vandalism, as if a passing horde of barbarians had come into the chapel to destroy one of the greatest paintings ever made by man, but Filippo understood at once that the barbarians were not a passing horde: they were resident in the city. The fresco had been defaced by someone with a grudge against Brancacci who, as Filippo remembered it, had been instrumental in Cosimo's exile. This had been a savage act of revenge. Therefore, Cosimo was the vandal. Could that be true? Certainly it was true that Cosimo had arranged for Brancacci himself to be exiled, but had he ordered the erasure of his image? Filippo could understand Cosimo's anger, but he could not sanction this act of destruction. Nor could he sanction the complicity of his Order.

Suddenly he felt trapped within the Carmine and its hypocrisies. He needed to leave now, at once. The cloisters were silent; all the friars were abed; he went to the stores and helped himself to another habit and two shirts – one should always have a clean change of clothes. Then he went to see whether a hole he had made himself in the western wall when he was a boy was still there. He pulled aside a shrub that had grown up and found that it was.

The last time he had gone through this hole was to see Brunelleschi's dome being built on the Duomo. He'd heard about the gigantic hoist and needed to see for himself the enormous winding drum and the vertical shaft driven by oxen, lifting huge loads of stone up to the double-shelled dome. He remembered the excitement so well: Brunelleschi's ingenuity and self-confidence had solved a problem that had seemed insoluble: how to build a large octagonal dome without internal supports or external buttresses. Now he was going through that hole in the wall that would lead him to supper with the great Brunelleschi at the Medici house tomorrow. Blowing a kiss to the Carmine, he squeezed through and hurried to the house of a relative to beg for lodging for the night.