A series of transparent slides are being projected onto a filmscreen in an extensive, luxurious office. Two men, initially offscreen, discuss them. When seen they are Sir Charles Portland and Villiers of British Intelligence.
The slides are holiday scenes, in no logical order, some over-exposed, some under-exposed, some correct. Sir Charles believes that there is a code somewhere in them that their code technicians have been unable to penetrate. Villiers is concerned that there is nothing at all.
The next slide – identified by Sir Charles as Number Six – shows an elderly man of foreign extraction, white hair receding from a thin face with prominent cheekbones. His name is Seltzman. But where is he?
The first part of the opening credits follows, until the Prisoner collapses unconscious on his couch in his flat. When he wakes, a new melody is heard, and the familiar catechism is omitted.
We see overhead shots of the Village, from a helicopter descending to land. It’s occupant is a man known only as the Colonel, who goes immediately to Number Two’s office, demanding to know what he has been brought there for.
The new Number Two, white haired, with a very assured manner, directs the Colonel’s attention to the surveillance footage of Number Six pacing in his cottage. The Colonel is not impressed.
Number Two asks him if he has ever heard of Professor Seltzman? Seltzman is a brilliant neurologist who has concerned himself with the transfer of thought and has, apparently, invented a machine that can transfer the mind of one man into the body of another. The Colonel is openly disbelieving. Number two enthusiastically describes it as the ultimate espionage tool, with which they could break the security of any country: just capture an agent and send him back with their own man’s mind in his body.
However, the Village doesn’t know where Seltzman is, and the only man who might is Number Six. But they have a Seltzman machine, and an Amnesia Room where they can erase a person’s memory back to a specified date (they are about to erase the last three weeks from a man who told them everything very easily, so he can go back and learn more).
Number Six’s memory will be erased back to the eve of his capture by the Village, and his mind will be transferred into the Colonel’s body. He will be returned to his flat in London, unaware of the Village, and he will then have to find Seltzman if he wants his own body back.
The Prisoner wakes in his own bed in his flat, musing about the things he needs to do today. There is a photograph on his dresser of an elegant, dark-haired woman, signed ‘All my love, Janet’, which he looks at closely. He goes through into the hall, passing a mirror, then steps back in shock at the sight of his new face and body.
A series of memories of his time in the Village threatens to break through his induced amnesia, but before it can do so, he is distracted by a knock on the door. When he opens it, it is Janet, asking excitedly if ‘he’ is here, ‘his’ car is outside. Unwittingly, he says that ‘he’ is here, but Janet quickly confirms no-one else is there and asks him anxiously about the missing man.
For a moment, the Prisoner plans to take Janet into his confidence, but her anxious questions make him realise that is inadvisable. Instead, he calls her Miss Portland (she is Sir Charles’ daughter) and claims to be a friend of the missing man,
He recollects his ‘friend’ telling him about Janet’s fitting for a dress of yellow silk, and is shocked when she tells him that that was a year ago: the last time she saw his ‘friend’. The Prisoner, shocked to find he has lost a year, gently hints at his ‘friend’s occupation and suggests he is on a mission for Sir Charles. He promises to bring Janet a message as soon as he can.
An angry Janet storms off to her father’s office, accusing him of knowing of her fiancé’s whereabouts all along and letting her suffer. Although he should not even tell her this, Sir Charles denies that the Prisoner is on a mission and ‘honestly’ states he does not know where he is.
Meanwhile, the Prisoner dresses in the same clothes as in the opening credits and drives his car to the underground car park. He enters the anteroom, where a different person, Danvers, is sat, He demands to see Sir Charles and, when Danvers asks who he is, grabs hi and begins shaking him.
Two guards calm things down. Whilst he waits to be seen, the Prisoner displays his (embarrassing) knowledge of Danvers, until Villiers arrives. Villiers requests his name: the Prisoner enquires whether he wants Code or Real.
His Code name is Duvall, in France, Schmidt in Germany, but Villiers would know him best as ZM73. He produces a photo of his real face. Villiers takes him to Sir Charles, where the Prisoner attempts to prove himself by reference to intimate family details. Sir Charles confirms the accuracy of these but points out that anything the stranger says could have been extorted from the real man by drugs or brainwashing. Frustrated, the Prisoner leaves: Sir Charles warns him he will be followed. An Agent named Potter is instructed to follow him.
On his way back to his flat, he is again followed by a hearse, but when he turns right, the hearse goes straight on and is waiting in his street when he returns.
The scene shifts to a large home where a black tie party is taking place. The Prisoner arrives in dress suit. A waiter hands him a glass of champagne: it is the Undertaker from the hearse. The Prisoner seeks out Janet and asks her for a dance. Though he was not invited, he has used his ‘friend’s invitation of a year before. He tells her that if she ever wants to see her fiancé again, she must give him the slip of paper that the man asked her to hold for him a year ago.
He waits in the arbour, musing over whether she believed him, but Janet turns up with the slip, eager for the message he has for her. First he caresses her face with his hand, then kisses her lightly on the left eye, the right eye, the tip of her nose, then her lips. She flings her arms round him and kisses him passionately, before breaking in realisation. He asks her who else could have given her that message, asks her to say only him: he needs her faith. Only you, she replies.
The next morning, the Prisoner attends a London camera shop first thing, reclaiming the transparencies being held under the receipt Janet has given him. They have been checked out before, by ‘clerical error’. Both the Undertaker and Potter observe him in the shop. He takes them home, draws the blinds. He writes Seltzman’s name on a sheet of paper then works out the alphabetical number for the even letters – E, T , M and N. Sorting out the respective slides, he superimposes their images in the projector. This reveals a composite message: Kandersfeld, Austria.
The Prisoner leaves for Dover. There is a homing device in his car, and Potter follows him. He travels through Paris, France and into Austria, stopping at a café in Kandersfeld, where a waiter welcomes him to the Village. The waiter identifies Seltzman’s picture as Herr Hallen, the barber and confirms he is still in Kandersfeld.
The barber is clearly Seltzman. At first, the Prisoner pretends to need a shave, but he quickly abandons this and explains who he is and why he is there. Seltzman is unconvinced. It is the same as with Sir Charles. However, the Prisoner convinces Seltzman that no two handwritings can be the same and, as Seltzman has sentimentally kept a letter sent to him, this can be proved (the letter is addressed to Portmeirion Road).
Seltzman sympathises with his young friend, and asks if he has been followed. They must not let themselves be taken by a side that does not have the Prisoner’s real body. Potter is first to arrive. The Prisoner tackles him and the two fight in Seltzman’s basin, until the Undertaker enters and gasses both into unconsciousness.
For a second time, a helicopter descends on the Village. Seltzman and the Prisoner in the Colonel’s body come to Number Two’s office. Seltzman has perfected the reversion process, but will only carry this out under his own terms, that he be completely alone. Number Two agrees, as he is having the entire process filmed.
Seltzman prepares his machine with the two unconscious bodies in place. He puts on an electroded cap and switches on. Lightning crackles between the three heads, subjecting Seltzman to extreme strain until he collapses.
Emergency services are called, but Seltzman is dying. The Colonel leaves for his helicopter.
‘Seltzman’ is fading fast. His final words to Number Two berate him for promising him the body was healthy and requesting that Number One be informed that he did his duty. Number Two’s puzzlement ends as he suddenly realises the implications of this statement, which is affirmed by Number Six, in his own body, sitting up and advising that Seltzman had gone further than any of them had suspected: he could transfer three minds between three bodies. The one he is in has gone free.
The helicopter takes off and flies away.
The Prisoner’s face races towards the screen. A pair of iron-barred doors slide across in front of it, slamming shut.