Roberts has always regarded Russia as a kind of disease. She caught it herself at the age of 14, and has so far failed to shake it off. In fact, she finds that as she gets older, she suffers more and more frequent bouts of it and has to go there two or three times a year. She was making quite a good recovery for a while in her 20s and 30s, working as a journalist on various newspapers, but experienced a severe set-back in 1981 when she married John Roberts, then the director of a Foreign Office-funded organization dealing with the Russians. The combination of frequent Russian visitors to their London home and visits both official and unofficial to what her husband calls "that country" made any prospect of recovery remote.

The possibility that the infection may be passed by close contact within families is raised by the fact that her elder daughter chose to study Russian at university before escaping onto the stage. Her younger daughter appeared as an opera singer to be immune, until she was caught practising Olga's aria from Eugene Onegin in the bath with a perfect Russian accent.The Roberts now live in a pine forest in Scotland where they have built a dacha and filled it with the usual quota of smelly old dogs and ikons in every corner. As one of their closest friends in Moscow says: "It takes all sorts, doesn't it?"