This is one of the three early Tara King stories produced by John Bryce, originally titled "The Great Great Britain Crime". When he was dismissed and producers Brian Clemens & Albert Fennell were brought back in, they completely rewrote the show, adding the framework story featuring Mother and his two aunts and inserting various scenes from previous installments from the Emma Peel era to bolster the action. Original writers Malcolm Hulke and Terrance Dicks were decidedly unimpressed with Clemens' "salvaging" of their script, objecting to the jokey handling of work they had submitted to the series in good faith. Of particular annoyance were the barbed comments about poor plotting and weak characterisation, plus the pointedly melodramatic score used to send up the events of their edition.
Malcolm Hulke and Terrance Dicks had previously introduced their villainous organisation in the titular Cathy Gale episode Intercrime (1963).
"This is the only episode of the sixth season in which Linda Thorson does not appear in the last scene." This was the seventh season. Linda Thorson was only in the seventh and last season. The sixth season starred Diane Rigg as Steed's partner.
In the closing credits, the music score is not the same as usual.
Steed's umbrella is seen to contain a sword or rapier.