Sir Anthony Blunt, who was a Soviet agent for 25 years, is routinely questioned and gives no answers, but is knighted and works as Director of the Courtauld Institute, and presents his interrogator with a puzzle in the shape of a doubtful Titian painting. He also does art restoration work in Buckingham Palace, where he gets into an interesting conversation with HMQ.
| Actor | Role |
|---|---|
 James FoxSir Anthony Blunt | Sir Anthony Blunt |
 Prunella ScalesH.M.Q. | H.M.Q. |
 Geoffrey PalmerDonleavy | Donleavy |
 David CalderChubb | Chubb |
 Ann BeachMrs. Chubb | Mrs. Chubb |
 John CaterRestorer (Robertson) | Restorer (Robertson) |
 Edward de SouzaCollins | Collins |
 Jason FlemyngColin | Colin |
 Gregory FloyRadiologist | Radiologist |
 Barbara HicksLady at National Gallery | Lady at National Gallery |
 Anne JamesonBlunt's Secretary | Blunt's Secretary |
| MMark PaytonPhillips | Phillips |
 Julia St. JohnReceptionist | Receptionist |
 Richard BebbConsultant | Consultant |