 He appears again in a minor role in "The Spy Who Came in From the Cold", again in the role of Smiley's assistant.Guillam is a major character in "Tinker Tailor Soldier Spy", which retcons the chronology of "Call for the Dead" to make Guillam only forty in 1973.At the outset of the book, the failure of a major operation called "Testify" has resulted in Smiley and the former head of the Circus, Control, being fired.