We’re back to diabolical schemes in this one, in which a rare stamp lead Steed and Cathy discover a planned coup. This is vintage stuff; lots of the action centres around an old fashioned stamp dealer, there’s some upper crust in the form of a stamp collecting peer, and some devilishness in the dentists chair.

Steed is in wheedling form: ‘Philately’s one of your interests isn’t it?’ he asks Cathy when he approaches her; later she goes and takes an assistant’s role in the shop just to avoid his clanging hints that this is what he would like her to do. She also challenges his methods – disapproving of the phone tap that originally put him on to the case. The polymath makes one of her rare mistakes at an auction where she accidentally successfully bids £50 for a stamp collection when waving at Steed.

There are yet more policemen in this one! Clearly the no-policemen edict was not build on a particularly long-standing tradition – although these policemen are not all they initially appear.

The most exciting guest star for me, in this, is the wonderful Richard ‘Slartibartfast’ Vernon. After Hitch-Hikers’, my favourite Vernon performance has to be Lord Emsworth (on the radio) but he’s more Roderick Spode in this.

The script is by Malcolme Hulke and Terrance Dicks who would both go on to become well known for their contributions to Doctor Who – perhaps this is unconnected with the fact that it doesn’t all seem to make sense, and the ending is a little weak with an unnecessary twist but a disappointing lack of action… That is a bit harsh, though, as it’s good colourful stuff – this is Dick’s first television credit, having been invited by Hulke to help when he became stuck. Their style suits this new fantastical Avengers well, and they would go on to contribute another three scripts together, and Hulke several more solo – including one of my absolute favourites!