After an amateur frogman is found drowned, four inches taller dead than he was alive, Steed and Emma go undercover at an ancient Scottish castle. There they must uncover the link between the Clan De'ath, and the recent disappearance of fish along the Scottish coast, without becoming victims of medieval torture themselves.

Perhaps being of Scottish descent makes this one more interesting for me, but I still think this is an excellent episode. The castle and countryside steal the show, even though it's not really Scotland. The only weak point is the plot which is rather "Bondian", but Gordon Jackson as Ian is one of the series' best guest appearances.

It's never quite explained why Angus would want to open the castle to the public when he has this extremely large, covert operation going on down below. It would seem to me that having multitudes of people around all the time would increase the chances of someone discovering what's really going on.

Also it's never explained how much knowledge that Ian had of things. He obviously had at least a sneaking suspicion that something was amiss, it would've been interesting to know just how involved he was... Or did he just turn a blind eye to things and try to pretend it wasn't there?

When Emma is first seen, from behind, driving up to the castle, she has blond hair. (Obviously a stunt double)

During dinner, Steed's glass is vibrating like crazy, but Emma's is not moving.

When Steed leaves to go fishing, he is wearing a dress shirt and coat as he walks out of the castle... He is still wearing them as he is seen walking through the castle grounds... But when he arrives at the moat, he is suddenly wearing his sweater.

When Steed emerges from the water in the frogman's outfit, it is not Patrick Macnee in the mask. It is obviously a stunt double as he has a much more prominent nose.

And speaking of stunt doubles, when Emma sneaks back up on the castle, later that night, she has blond hair again. (Obviously the same stunt double we saw at the beginning)

When Steed is chained up in the dungeon, he works at trying to squeeze his hand out of the shackles. Yet when the guard approaches, he simply knocks him out by pulling the chain out of the wall! Why didn't he do that in the first place? :-)

When Angus runs up the stairs, as he is being chased at the end, his kilt flies up and his "unmentionables" are showing.

  - Courtesy of David K. Smith / The Avengers Forever

Emma exits the door to the dungeon and spies somebody. The next shot, she's behind the dungeon door again.