The night grows deeper but the prayers still go on, sporadic at first and then in unison, resounding through the grottos like so many oracles. Across the river a group of young men are drinking from beer cans. When he gets up close to them he realises they’re telling jokes, most of them concerning religious themes.

‘Did you hear the one about the actress and the bishop?’ a red­headed boy enquires. When he gets to the punchline there’s the generous laughter alcohol always brings to a witticism, and a polite round of applause.

When the noise dies down they talk about what will happen later tonight at the discotheque, about the women they’ve been chasing for the last few days, the excitement of seducing devout young mademoiselles from conservative homes.

‘I hope it’s only the statues that go in for this virginity lark,’ the boy in the freckles intones, a remark that draws more laughter from the others. They cackle at him as he speaks, their feet stamping raunchily on the ground.

Behind them in a tent a different kind of conversation is going on, a delicately-boned nun discussing the prophecies of an ancient saint with her friends, discussing the fact that there may only be one more Pope before the end of the world, and that a black one.

‘As long as it’s not another Pole,’ a round-faced man sitting opposite her whispers, and she stares sternly at him. ‘I’m a Pope Paul man myself,’ he goes on. ‘John the 23rd opened the windows to let the cobwebs out but he brought in a tornado instead of a breath of fresh air. Personally I think he threw the baby out with the bathwater.’

He sips gently at a glass of wine and deals cards for a game of whist. Across the table from him the nun looks concentratedly at her hand for a moment, then drops it on the table. ‘I can’t help thinking about that armless woman we saw today,’ she says frowning, ‘‘It got me thinking about the stupid little things we moan about in our lives.’

A jolly-eyed man with a bald patch agrees with her as he looks at his own hand of cards, reaching into his pocket every now and then for money for a bet.

‘We all have our crosses to bear, Sister,’ he says, ‘be they physical or otherwise. Sometimes I think the handicapped people are happier than any of us. They look that way to me, anyway. And of course it will all be made up to them on the last day.’

‘Whom the Lord loveth he chastiseth,’ the round-faced man pronounces. ‘Though if that’s actually the truth, I think I’d prefer to be despised.’

The orderly walks down by the stream. It gullies gently beneath him like water swivelling down a plug-hole. The pilgrims are at the top of the hill by now and are bent in adoration. As he looks at them, something about the starkness of the situation moves him. He thinks for some reason of medieval times. He listens to the rustle of their garments as they shift from knee to knee, listens to the whispered prayers that seem to be carried by the wind like doves to the brow of the hill.

Across from him a woman is holding her baby so tightly she seems to be on the point of suffocating it. Another one gives her child a pill when the pain becomes bad. There are men in uniforms selling holy water, emaciated figures on stretchers who give slight waves as he passes. Many of them have their eyes closed in prayer, as if they’re reaching some kind of revelation the outside world has no right to intrude upon.

When he gets to the office he signs himself in. He feels a hand on his shoulder, and when he looks around it’s Peter Gallagher, the group leader.

‘Well,’ he says, beaming over at him, ‘Not much longer to go now. How do you feel?’

‘Tired,’ he says, hoping the remark will dissuade Gallagher from pursuing the conversation. But it seems to have the opposite effect.

‘The first time I came here I was shattered. It was a week after I got home before I was myself again. It’s the psychological drain rather than the physical one that gets to you eventually.’ Something in the man’s tone of voice rankles with, as it’s rankled all week. He can’t put his finger on the reason.

‘So what’s the story for tonight?’

‘I’m afraid you’re on the graveyard shift with Mrs.Hanratty again. Do you think you can hack it?’