John Drake is in Vienna, working with the American Ambassador (Charles Carson) in order to discover who’s been leaking US secrets. All the evidence points to newspaperman Harry Logan (Robert Flemyng) but Drake isn’t convinced …

Having recently completed a brisk rewatch of The Prisoner, it makes sense to rewind a little and tackle Danger Man as well, although given that this series has far more episodes it’ll be a slightly lengthier undertaking.

Still, we’re on familiar ground as the first actor we see is Peter Swanwick (“orange alert”, that was his catchphrase). But Swanwick doesn’t have much to do as his character (Joe) is snuffed out by Alexis Buller (Charles Gray) before the opening credits roll.

The 25 minute format obviously doesn’t give you a great deal of time to develop plot or characters, but I’ve few complaints with Jack Whittingham’s The Key. Keeping the cast small helps in this respect – although the downside is that it’s not too hard to work out whodunnit.

But there are a few misdirects along the way. Since the unfortunate Joe knew all about the secrets leaked, I wondered if his death was significant. But unless I’ve missed something it seems not (indeed, I’m not quite sure why Joe was killed or why Drake, upon learning that Joe had access to the secrets, didn’t consider that his murder was worth investigating). Drake then briefly wonders if the Ambassador might be guilty (the British born Carson appears to be dubbed throughout – maybe American accents weren’t his forte).

Both Logan and his wife Maria (Monique Ahrens) are charming, so they too seem to be out of the running. But since we’ve dismissed all the possibilities, something isn’t right – and eventually Maria is revealed to be the spy.

After Drake, apparently simply making idle conversation earlier in the episode, discovers that her family still lives in Budapest it seems obvious that she’s been blackmailed by the authorities (with the continued well-being of her family used as a lever). A tearful Maria later tells her husband this, and the episode looks to be almost wrapped up.

The additional twist – Maria is in love with Buller and has been playing Logan for a fool – is well done (I admit that I didn’t see it coming). Both Robert Flemyng and Monique Ahrens are excellent throughout and it’s surprising to learn that Ahrens only clocked up a handful of  film and television credits, as she’s very effective here.

The ending – Logan and Drake eavesdrop on an intimate conversation between Maria and Buller – is a memorable one. Neither Logan or Drake are called upon to say anything but the range of emotions that flit across Flemyng’s face as he learns the truth speaks volumes. With just a brief, downbeat spot of narration from Drake, that wraps things up.

The James Bond movies might have kickstarted the insatiable appetite for spy films and tv series during the 1960’s, but it’s worth remembering that Danger Man got there first (this episode aired in late 1960).