First broadcast 8th October `1979.

'Ricki Tarr has not lied to us. He has simply done what agents the world over do: failed to tell us the whole story.'
Smiley has realised that Source Merlin is run by Karla from Moscow Centre and he has told Lacon so. Now he decides the time has come to call on Jim Prideaux.

George Smiley: Alec Guinness
Peter Guillam: Michael Jayston
Lacon: Anthony Bate
Mendel: George Sewell
Jim Prideaux: Ian Bannen
Sam Collins: John Standing
Control: Alexander Knox
Bill Haydon: Ian Richardson
Molly Purcell: Mandy Cuthbert
Roach: Duncan Jones
Spikely: Daniel Beecher