The Avengers Series 3 Episode 14: Dressed to Kill

This is one of the series three episodes later rewritten to become a series five episode, The Superlative Seven, even influencing other later episodes.
The point of the episode is not the party on the train, the point is that Steed goes to this obviously fishy party, taking Mrs Gale with him, seeing it as suspicious that he has been invited to this party supposedly held by a friend who is actually in Argentina. This episode has been criticised for the apparent plot weakness that Steed does not reveal to Mrs Gale that he is suspicious of the invitation until relatively late in the narrative. This has been interpreted as meaning that this is therefore a story in which Steed knows that World Ward III has just nearly broken out but is only interested in going to a party, and that the late revelation that Steed knew the party was suspicious is a mistake or poor  writing.
My personal opinion is that this is to sell this story very short. I feel that if Steed had told Mrs Gale his doubts about the invite when it would logically come in the story - at the beginning - this episode would actually lose much of its interest. In fact at the beginnign what he does tell her of the gravity of the situation and the radar station at Smallwood, lays the groundwork in the viewer's mind for there to be something major at hand, despite the connection with the party not being apparent. Perhaps much of the point of this episode is the fact that Steed knows but doesn't tell, which leaves both Mrs Gale and the audience in the dark.
Another possibility would be if Steed had told Mrs Gale the party invitation was suspicious before it was revealed at a later point of the episode. Of course when he does refer to it, it comes across as the first time he has told her, with no indication that he is referring to something he has already told her. The deceit is reinforced by Mrs Gale's sneaking onto the train in her fancy dress: when she arrives we don't know that it is her, and the deceit motif is also echoed in the relabelling of a small deserted station as Wolverhampton, and also by Steed seeing Mrs Gale in her fancy dress and not telling the other characters. 'The place is deserted', he says shortly afterwards. Even the baddies, posing as the train staff, are unaware that their boss is one of the guests on the train.
The element of secrecy actually allows for an interesting dynamic to develop between Steed's and Mrs Gale's characters in this episode: frequently she is portrayed as the brainy one, the serious one, the responsible one. She is also aware of her intellectual superiority to Steed. In this episode, not only is the action dependent on Steed's knowledge and sole responsibility for acting on what he knows, but Mrs Gale goes along with this, apparently without question. This is a change from the normal tension in their relationship, where they do tend to circle round each other somewhat.
Another interesting aspect of this episode is how purely Avengers it is. From the bizarre collection of things left in Steed's flat after the party to the mere fact of holding a new year party on a train, this episode *feels* more like a series five or even six episode, suggesting that Brian Clemens already had the ideas that would make the later Avengers what it was. Once again, I feel that to focus on the logical failures in the device of trapping all the possible buyers for the land on a train, is to miss the point of the episode. Yes, the effect could have been achieved without this device, but that would once again reduce the episode to a straightforward detective story without its Avengers overtones.
Conversely the plot device of marooning a group of people in an isolated place with one or more killers around or among their number, is a staple of detective fiction, found in Agatha Christie amongst other writers. The characters respond in the way you would expect, with suspicion and even paranoia. Interestingly, in both this episode and The Superlative Seven, Steed's unnecessary mystification of what he actually does makes him look merely suspicious: maybe the intention is to cast suspicion on him as one of the protagonists, so that he remains in the forefront of the plot.
One of the most archetypally Avengers things about this episode is that all of the guests at the party are coincidentally signing deeds for land on New Years Day - not excessively likely - but also all are willing and able to abandon home, family, and friends, and go alone to a party which they think is being held by a friend. What makes this so Avengers is the Avengerland feel to it - the action of the story takes place in isolation. There are - as it were - no people other than the ones involved in the story. The other people who turn up for the party - presumably also invited - and go into the other carriages are merely scene-setting. There is no real reason why they need be there at all, apart from to have a body of people to celebrate the significant ones from. They merrily go off in the rest of the train and are mentioned no more. An England where solicitors work on New Years Day, people go alone to New Years Eve parties without question can only be in the world of The Avengers.
I like this Avengers episode enormously, because it is an Agatha Christie novel transposed into Avengerland. I feel it works very well - better than The Superlative Seven, its later rewrite - largely because of the things mentioned above that are sometimes thought of as weaknesses but which I feel actually make the episode what it is.