It was such a corking day and I had so much time in hand that near the Sorbonne I stopped my cab, deciding to walk the rest of the way. And I had hardly gone three steps and a half when there on the pavement before me stood old Biffy in person. If I had completed the last step I should have rammed him.

'Biffy!' I cried. 'Well, well, well!'

He peered at me in a blinking kind of way, rather like one of his Herefordshire cows prodded unexpectedly while lunching.

'Bertie!' he gurgled, in a devout sort of tone. 'Thank God!' He clutched my arm. 'Don't leave me, Bertie. I'm lost.'

'What do you mean, lost?'

'I came out for a walk and suddenly discovered after a mile or two that I didn't know where on earth I was. I've been wandering round in circles for hours.'

'Why didn't you ask the way?'

'I can't speak a word of French.'

'Well, why didn't you call a taxi?'

'I suddenly discovered I'd left all my money at my hotel.'