After three hours with Opus Dei women at Ashwell House in east London I wandered west, half-stunned, like a cat hit by a car. At Oxford Circus the usual loons were saving souls: ‘Repent now, turn to God!’ from a woman on the south side. From a north-end traffic island, megaphone man provided the antiphonal response: ‘Seek salvation before it is too late!’ And in my pocket my mobile, ringing with a message from an Opus Dei publicity man. ‘Hi there! When you’re finished at Ashwell House, come to Notting Hill to have tea with Sebastian. He’s a supernumerary and he plays the cello! I think it’s important that you meet him.’

Maybe, but I wasn’t sure I could. I’d had enough. It wasn’t that Opus Dei had been unexpectedly sinister or murderous, like Silas, the anti-hero of The Da Vinci Code — after all, St Josemariá Escrivá beat himself till he bled, so I’d been expecting, hoping for, gothic. It wasn’t even that they were sallow and enigmatic, like Ruth Kelly, Opus Dei’s representative in the Cabinet. Instead, the members I’d met had been so mysteriously well-balanced and comfortable in their skins as to be actually frightening. If I had to sustain eye contact with another well-adjusted, devout young Catholic, I thought I might start swearing, or crying.

Ashwell House, a hall of residence for female students, is owned by Opus Dei but open to all — some students are members of what’s known as ‘The Work’, some are agnostic. It’s a business and, like most Opus Dei operations, self-supporting, impeccably run — a testament to the efficacy of Escrivá’s grand idea: that lay Christians can seek holiness not despite the daily grind, but through it.

I was shown around by Ashwell’s directors, Eileen and Sam, both 40 or so, both numeraries of Opus Dei — celibate, devout, wearers of the now famous cilice, a spiked chain strapped around the thigh for an hour or two most days to mortify the flesh.