Getting to the moon was a 1960s obsession, but few people expected the place itself to be anything more exciting than a big lump of rock. Even the writers of Space Patrol didn't populate it with the kind of fantastic creatures they invented for Saturn, Neptune and Jupiter but just made it the inhospitable hideout of a gang of space terrorists (sorry to spoil the mystery). And these terrorists originate from Earth: the show's first indication that the planet that's set itself up as the galactic centre of peace still has problems in its own backyard.
The episode gets off to a thrilling start with the explosion of a group of buildings which, for some unexplained reason, look like cakes.
It seems that these are office blocks, and more than 40 people are injured in the explosion (we're not told if anyone's dead, that sort of thing isn't done in children's programmes). What's more, the shockwaves cause normally pristine Venusian Marla to become quite disarranged.
Marla assumes it's an earthquake that's knocked her off balance, but her boss Colonel Raeburn knows better: the explosion was caused by a death ray fired from outer space. And it's not the first one. Having decided upon the moon as the likeliest origin of the beam, Raeburn sends Captain Larry Dart and his crew to investigate. Here they are being decontaminated before they head off.
The most interesting occupant of the moon that we get to meet is Sam Marsden, an aged prospector on an eternally futile quest for moon diamonds (played, in characteristically economic style, by the instantly-recognisable puppet that usually takes the role of Raeburn's irascible superior).
The presence of an old prospector on the moon, like Matt Matic's Walter Brennan act in Fireball XL5, is a link to the backward-looking Western motif that dominated boys' entertainment before it was usurped by tales of rockets and robots (Four Feather Falls making way for Supercar and Fireball XL5). The two genres would later be placed in conflict to brilliant effect in Toy Story - by which time the Space Age was just as much an object of nostalgia as the Old West.
Huge chunks of Mystery on the Moon consist purely of interminable shots Larry Dart chugging around the uninspiring lunar surface on his floating scooter searching for a mysterious new crater Sam claims to have found. It's hypnotically dull stuff.
When Larry finally does locate the crater he finds it to be the origin of the ray, manned by a gang of ruthless crooks notable for their peculiar facial hair.
This lot have just contacted Colonel Raeburn to demand lots and lots of money to stop them blowing things on Earth up. They're clearly tough customers: their leader (who goes by the splendidly incongruous name of Berridge) sounds like Lionel Stander from Heart to Heart, while his second-in-command is not the first Space Patrol character to sound uncannily like Coronation Street's Phyllis Pearce.
Dart and Raeburn decide to consult comic relief scientist Professor Haggerty to see if he's able to find a way of vanquishing these rotters. According to Raeburn, Haggerty is "As Irish as ever. And that means part madman and part genius." The madmenius's idea is to set up a giant mirror towed by Dart's galasphere which will bounce the beam back and blow up Berridge's base (try saying that after a few Guinnesses). I'm sure he's come up with this mirror scheme before, you know.
The project requires a special reflective paint only available from Japan, which leads to a scene with Raeburn requesting it from an only mildly racist puppet.
Anyway, the scheme's a success and the ray destroys the base, with Berridge and his men all dying a horrible fiery death. Hooray!
Should you wish to do so you can see Mystery on the Moon here.
Next tonight, it's carnival time for our favourite reformed gentleman thief (I think it's the thief bit that's reformed) in:
Mexico City, to be precise. There Simon Templar meets an old friend, Miguel Artigas , "the greatest acrobat in the world". He's played by Alex Davion, last seen playing a different role in this very show just a couple of weeks back. This opening scene is comprehensively stolen by a debauched gnome having a whale of a time in the background.
The episode's title character (played by Lana Morris) is the widow of Gaspar (pronounced "Gasper" by many of the cast), a man who attempted to assassinate the president, then met his death shortly after Teresa herself drew attention to him (not realising it was her husband). But she doesn't believe he's dead, and she's determined to find him. Look at that face. See? Determined.
Meanwhile, Simon meets Miguel's decidedly camp partner (ahem, in his act), Pedro (sadly the actor who plays him is uncredited). "Pedro objects to my discipline," Miguel intriguingly informs Simon.
By the kind of coincidence that motors shows like The Saint, Teresa turns up at Pedro's caravan - he was her husband's best friend, and she thinks he can help her find out his current whereabouts. He declines to help, but nearly meets his death at the hands of sinister knife-thrower Marne Maitland. However, this attempt on the acrobat's life is interrupted (like so many things in life) by a girl walking past with a snake.
His second try, this time with a gun while Miguel's performing, is more successful.
Simon, Teresa and a hysterical Pedro gather round Miguel's deathbed (where he's tended by an uncredited Walter Randall), to hear his last words. With his dying breaths he confesses to Teresa that he hid her husband on a lorry to San Pedro, rambles on about Santa Brava ("The brave saint," Teresa obligingly translates for the viewers at home) and holds up four fingers.
Simon, of course, takes the reference to the Brave Saint to refer to himself, and insists on accompanying Teresa in her quest. On their way to San Pedro they're followed by Marne Maitland, his character a genuinely scary psycho who happily offs both future Coronation Street star Alan Browning as a caféowner working for the police and Paul Whitsun-Jones (also last seen in The Saint just two weeks ago) as a mechanic along the way.
Stopping at a hotel in San Pedro, Simon and Teresa visit Miguel's mother (Marie Burke), who sheltered Gaspar for a short while, and now spends most of her time tending an enormous shrine to her son.
They also pick up a hanger-on in the agreeably sleazy form of Eric Pohlmann as Casemegas. He claims to be a travelling salesman, but knows too much about the pair of them and Teresa's husband for that to ring true.
This mysterious chap proves especially mysterious when he picks up the pair in his car after they only just survive their wicked stalker cutting the brakes of Simon's car.
Eventually the three of them find themselves in the court of bandit king El Rojo (Lawrence Dane), who claims to have had Gaspar as a member of his camp for a short while, before the would-be assassin threw himself off a cliff.
Teresa's choice to be secretive is undone when Casemegas (who reveals himself as a policeman) figures out that El Rojo is himself Gaspar. There's not much time for this revolution to sink in before Gaspar dies at the hands of the sinister knife-thrower, who is himself rapidly dispatched by Simon. As Gaspar expires, Teresa tells him she loves him - after he's dead, she reveals to Simon that she was lying: she's in love with another man, and all along she'd wanted to know for sure her husband was dead rather than find him alive. It's an agreeably dark twist to end an especially gripping Saint.