Without giving anything away, there is a doll in this episode. It's used as a plot device.
Of what significance is that? None really, except perhaps for Danger Man / Secret Agent trivia buffs. You see, there was also a doll employed as a plot device in the masterpiece of an episode 'Sting in the Tail'. That's the episode where John Drake uses an assassin's femme fatale girlfriend to lure the killer to Paris in order to arrest him. The connection is that both episodes were written by Philip Broadley.
Interestingly, Philip wrote another episode, 'You're Not in Any Trouble Are you?', which starred the same pretty woman as in this episode (Susan Hampshire). And guess what significance that is, other than both episode titles ending with a question mark and Susan experiencing a migraine in each installment? Broadley again used a doll as plot device. Did this make the episodes boring? Repetitive? Certainly not! It was a different doll in each story, and more importantly the plots were quite different. I guess the writer simply found that dolls and femme fatales go well together.
In any case this is a pretty good episode. A fine example of John Drake doing what he does so well.. turning the tables on his opponents. Which brings about a very satisfying ending to this installment.
By the way, if you like romance there is a delicious dance played out between Drake and Susan Hampshire's character; Lesley Arden, when John and Lesley dine at her apartment. It's the kind of dream date that we all dream about. At least up to the point where Lesley tries to kill Drake. But that is giving something away and I promised not to. But hey... it's Secret Agent! ;>
Be seeing you...