Recently separated Phil Ockerman falls hard for Bertha Strunk at a tango lesson in Clerkenwell. Bertha also bears a strong resemblance to the seventeenth-century Venetian singer and composer Barbara Strozzi (with whom Phil happens to be obsessed), to the point where Phil is no longer sure which is which... Navigating several London Underground lines and considerable planetary activity, Russell Hoban's intriguing romance tangos its way through a world...