City of Death was one of those where the villain stood out so much I could still remember him very clearly even though I was about ten at the time (yes I know, that makes you feel old). Rewatching it, it's one of those where you get the feeling that there's about twice as much plot as the episode could reasonably hold -- which is not necessarily a bad thing -- I certainly enjoyed it (as opposed to some of the early Jon Pertwee ones where I think the script said "run around a gravel pit for five minutes while we write more dialog"). Plus it has John Cleese.