That Agatha would get on to a yak in company with a lover even in the comparative seclusion of Tibet is unthinkable. I very much doubt if she’d do it with her own husband in the privacy of the Simplon tunnel. But poetry, as I’ve remarked before, should always stimulate the imagination.

By the way, when you asked me the other day to dine with you on the 14th, I said I was dining with the duchess. Well, I’m not. I’m dining with you.