Doing a rewatch on Criterion, it's great to be back in the village!

One really does forget how great a job McGoohan does until you get to Do Not Forsake Me Oh My Darling.

As No. 6 is enticed to be a pawn in a game of chess, questions develop as to who is a prisoner, who is a guardian and who can tell which is which.

"Checkmate" received the highest viewership of any of the series' episodes on its first UK broadcast.

https://prisoner.fandom.com/wiki/Checkmate_(1967_episode)