It is 3 a.m. I have risen, as men of a certain age are wont to do, to answer a call of nature. Emerging from the smallest room, torch in hand, for I am staying with friends and the way is unfamiliar, I pass one of the innumerable bookcases which adorn every wall of every room. Each shelf is packed to bursting with an embarrassment of riches. I stop to look through them, as one does at 3 a.m., and notice on the bottom shelf a slim, grubby volume, its spine illegible. Curiosity creeps into my fingertips. Crouching silently, I prise it from its neighbours and fancy, as I blow several years of dust from its pages, that I can almost hear this little book sigh with liberation.