I am of the opinion that No.34 was a plant, sent to infiltrate the Village, that the body found on the beach that morning in 'Dance of the Dead,' was No.34, who had been under surveillance by observer-No.240, who had got to know No.34, but who didn't know her!
But why did No.34 die? It's possible he was drowned in the water, possibly by the Village Guardian. But I shouldn't think that No.34 was listening to his radio at the time of any such attack, because the radio would have been lost. No.6, you will recall, found the radio in it's waterproof pouch in the dead man's pocket. How No.34 was able to smuggle such a transistor radio into The Village in the first place, is unknown. But perhaps they had a man working in Administration!
Certainly I believe the radio massage listened to by No.6, was really meant for No.34, but he was dead by that time, a message which he would not have liked to have received. Apparently the appointment could not be fulfilled, that there were more important things to do that night. It seems to me that No.34 had been "hung out to dry" by his own people, that they would not be coming for him! I wonder how No.34 felt about that?
But this is not the first time such a Village has been infiltrated, John Drake managed to do that, the time he went behind the Iron Curtain to infiltrate Colony Three. This to find out where so many people had been disappearing to. People with specialist knowledge, or expertise, who were recruited to Colony Three, who once there, cease to exist. But luckily for John Drake, his people had an agent in Section 1!
Number 6 - A Plant?
What if No.6 is a plant, sent to the village to check on security, to check on No.2? That idea makes a total hash of how we see the opening sequence, that of a man who having resigned is trying to get away before they come for him. That would all be an act, as he allows himself to be abducted, as the Prisoner goes to work undercover in the village Absurd? Well Nadia Rakovsky allowed herself to be abducted, to attempt a fake escape and be subjected to the awful effects of being captured by the village guardian! To make no mention of being interrogated and subjected to torture in that interrogation room, as she was a plant, working undercover in the village. Oh I know what Nadia Rakovsky allowed herself to be put through is nothing compared to what No.6 was put through. But the principle is the same.
Certainly whoever No.6 is he is definitely a spy. He has intelligence of working with codes, uses code names, Schmidt, Duval, D6, ZM73, XO4, and a false name of Peter Smith. He gives nothing away about himself, only that of his birthday 19th of March 1928, the only real thing we know about the Prisoner-No.6's identity.
It isn't until his supposed escape in ‘The Chimes of Big Ben’ that we see that his cover is blown! the Colonel and Fotheringay have been brought to the Village to help extract certain information from an old ex-colleague, and is left dumped in the village. Now he really is a Prisoner, betrayed by his very own people! But the Prisoner is still loyal, as we see in Many Happy Returns when the Prisoner "runs" again, back to old friends and ex-colleagues. And in ‘Do Not Forsake Me Oh My Darling’ we not only learn that this one time spy, and undercover man is engaged to the bosses daughter, Janet Portland, and that the Prisoner's direct boss, above the Colonel is Sir Charles Portland. The fact that ZM73 had been sent on a mission deep under cover for the past year, means that even Sir Charles Portland was not privy to such delicate information. After all, Sir Charles may have told his daughter under pressure by her!
Be seeing you