"Hugh, what can I say?" reflects the weary architect after a hideous weekend. He sounds, in the immortal phrase of P.G. Wodehouse, like a man who has just been hit round the head with a sockful of wet sand. "The bridge is moving in a way that they didn't predict. You think what might happen in life, you make conjectures, and then things happen beyond your wildest dreams. I'm surprised, disappointed, obviously very concerned. I've had all kinds of reassurances. It's safe. But the first priority is to get to the bottom of this."

A fix will be found, the wild snake will be tamed. The bridge, like the similarly audacious London Eye by Marks Barfield which also had its teething problems (remember how they couldn't raise it into position at first?), enjoys enormous public goodwill despite the glitch. As Foster points out with gloomy satisfaction, nearly a quarter of a million people crossed the bridge in its first weekend. Gloomy, because by then he knew that the bridge was about to be closed in order for the engineers to sort it out. So he sounds hurt. He also sounds angry.

I tell him I wish I could have listened in on the phone call he must surely have made to his engineer, Tony Fitzpatrick, at the legendary Ove Arup Partnership, as their bridge hit the headlines for all the wrong reasons last week. Foster barks a mirthless laugh. "It was one continuous phone call," he remarks, "over the whole weekend." And I think: if there's one person whose shoes I would least like to have filled last weekend, it would not be Norman Foster's. It would be Fitzpatrick's.