[1] The film depicts British MI6 agent Alec Leamas' mission as a faux defector who is given the task of sowing damaging disinformation about a powerful East German intelligence officer.
Just when it seems that he has successfully discredited his target, however, Leamas is revealed to be an active British intelligence agent disseminating false information.
Leamas is approached by a series of operatives, each one passing him up the chain of the East German intelligence service, and he expresses a willingness to sell British secrets for money.
He eventually flies to the Netherlands to meet an agent named Peters, who decides that his information is important enough to send him on to East Germany.
The evidence is circumstantial, and though it seems to implicate Mundt, Leamas repeatedly rejects that conclusion, claiming that an important East German official could not have been a British agent without his knowledge.
However, Fiedler is able to independently confirm Leamas' information and comes to the conclusion that Mundt, his supervisor, has indeed been a secret asset of British intelligence for many years.
They're just a bunch of seedy squalid bastards like me, little men, drunkards, queers, henpecked husbands, civil servants playing "Cowboys and Indians" to brighten their rotten little lives.
Today he is evil and my friend.Leamas and Nan arrive at the Berlin Wall and are given instructions to climb over to West Germany on an emergency ladder while a searchlight is intentionally turned away.
One exception is that the name of the principal female character in the novel, Liz Gold, is changed to Nan Perry in the film, reputedly because the producers were worried about the potential confusion in the media with Burton's wife, Elizabeth Taylor.
"[6] Variety called the film "an excellent contemporary espionage drama of the Cold War which achieves solid impact via emphasis on human values, total absence of mechanical spy gimmickry, and perfectly controlled underplaying.
"[7] Philip K. Scheuer of the Los Angeles Times wrote: "It is not an easy, certainly not a pleasant, picture to sit through; too impersonal, too objective, to move us to weep, so that its ending can only leave us tremendously depressed.
"[8] Richard L. Coe of The Washington Post declared: "Not having shared the evidently widespread admiration for The Spy Who Came In from the Cold in its original form as a novel, I nonetheless find it a wholly absorbing picture.
"[9] Brendan Gill of The New Yorker called it "in every respect an admirable translation [to] the screen of the fantastically popular thriller by Jean [sic] le Carré.
Extras for this version include: digitally restored picture and sound; an interview with John le Carré; scene-specific commentary by director of photography Oswald Morris; a BBC documentary titled The Secret Center: John le Carré (2000); an interview with Richard Burton from a 1967 episode of the BBC series Acting in the '60s; a 1985 audio interview with director Martin Ritt; a gallery of set designs; the film's theatrical trailer; and a booklet featuring an essay by film critic Michael Sragow.