It was proposed for a start that their meetings should take place in a secluded boat-house, but this meant that Guillaume would have to take up sailing, which he thought would be found to sort oddly with his known aversion to sporting activities, and in the end they agreed to meet quite openly in and around Bonn. So openly, in fact, that Kretschmann would occasionally come to the Chancellery and have Guillaume summoned on the house phone. But usually they met in restaurants and bars, often for convivial evenings with their wives present. Guillaume says that Christel and Nora got on well together, and if this is true then these occasions must have been one of the brighter spots in his wife's bleak life.

The Kretschmanns had been fictionalised long before I got near them. They were a married couple, names unknown, who had been sent separately to the West, as 'Franz Tondera' and 'Sieglinde Fichte', and they had begun by establishing separate and very different cover stories. According to Guillaume in his memoirs, Franz travelled for a well-known firm in the motor industry (he doesn't say which), while Sieglinde, having given up her training as a vet in the DDR, worked on a factory production line with Turkish and Greek women guest-workers. They were then directed to make each other's acquaintance by chance on a ski-ing course, fall in love, conduct a bashful courtship and get married all over again. So now Sieglinde Fichte of Ulm, otherwise Ursula Behr of Stuttgart, was Sieglinde Tondera of Cologne. Except that the Tonderas for some reason became Arno and Nora Kretschmann (their given names were extracted, according to the Spiegel, from a rearrangement of letters in 'Tondera'.) When the Guillaumes were arrested, the Kretschmanns, in all their shifting avatars, vanished, and even the most diligent searches since the collapse of the DDR in the files of the Stasi, the source of so many revelations about so many people, have so far uncovered no trace of them.

A number of other questions about the case remain unanswered. Exactly what information, for a start, did Guillaume pass on? He preferred to report to his controller orally, and his information - certainly before the election campaign of 1972, when he first had access to documents came by his own account chiefly from office gossip. Files and notes, Brandt is reported to have said when he gave evidence at the Guillaumes' trial,1 were much less important than the insights he could have got from informal functions. Various journalists covering the case filled in the likely circumstances.