From the title of this post, I'm sure you've figured out that I'm talking about the original TV series, and not the remake that's airing next week. Also, I'm sure you were able to intuit that I'm really enjoying the series.
The premise is thus: The title character is a member of the Brittish Intelligence agency, and one day spontaneously decides to resign. While packing for a "I just angrily quit my job" vacation, some mysterious men gas his home, and kidnap him. He awakes on an island with no name, in a village with no name, populated by people with no names, just numbers. The two consistent characters are the Prisoner, who assumes the number six, and Number Two, who is the adminstrator of the island. Saying that No 2 is a consistent character is a misleading however, as the character is replaced just about every episode, and even frequently changes genders. No 2's primary goal is to extract information from No 6, most specifically, they are constantly trying to find the reason for his resignation. Apparently he stated it was a matter of conscience, but the runners of the Island want to make sure. It is not clear who the powers behind the Island are. they could be parts of his own government, or they could be rival governments. Certainly the island contains two types of prisoners: People who know too much to be let loose, and enemy agents that need to be subverted, and intel extracted from. In addition to prisoners, the island also has guards, but everyone is simply assigned a number, with no way to differentiate which is which. The guy who serves you coffee? Guard? How about the radio repairman? Maybe a prisoner?
Every episode features a new plot by No 2 to try and trick or force No 6 into revealing why he resigned. Through this we come to realize that No 6 has superhuman resolve, and refuses to reveal any information, and continuously attempts escape regardless of his past failures.
One other "character" I feel I should mention is Rover, the Island's perimeter guard, and quite possibly the most terrifying balloon in existence (being latex sensitive, I have considered many balloons terrifying) Whenever an escapee gets to close to a means of egress, Rover is dispatched, and hunts them down with an eerie howling noise, quickly overcoming it's prey, and smothering them, either until unconcious, or dead.
One of the most interesting episodes so far had to deal with them sneaking into No 6's room, and brainwashing him under drugs to think that he was left handed. They then brought in an imposter to take No 6's place, while telling the real No 6 that he was the impostor. It would seem that they intended to make him start to doubt his identity and then hopefully become their man in the end. It doens't play out that way of course, but it's a fun ride anyway.
Another great episode involves No 6 managing to fool the current No2 into thinking that 6 is actually a plant from the people that run the Island, who has been sent to evalute 2's mental state. Driving him to paranoia and isolation from all his supporters. It was a relaly amusing episode, and nice to see No 6 get his blows in during the ongoing mindgame.
As such, the Prisoner doesn't rely much on special effects, and avoids looking dated in all areas but fashion, which at the same time seems kind of fitting with the Island. The only real special effect is Rover, which still manages to evince a great amount of menace, despite it's humble construction.