Directed by David Elliott
Teleplay by Alan Fennell
First UK Broadcast – 21st February 1965
For a series often praised for its warmth and humour, Stingray also does spooky and unsettling very well. Stories like The Ghost Ship and The Ghost of the Sea aren’t afraid to ditch the cosy and colourful family atmosphere for a short while and take on a more mysterious and eerie feeling. Invisible Enemy cranks that all up to eleven and isn’t afraid to alienate the audience with an entirely new type of threat. The villain this week isn’t another shiny-faced green bloke from under the sea – but an ordinary man badly in need of a shave and a new watch. Yet he proves to be quite a match for the gang at Marineville…




At some point, someone, somewhere must have said to the AP Films team – “Look, that gimmick of starting the show in black and white before gloriously transitioning to colour isn’t going to impress that many people in a few years time, so you should probably just do the whole thing again in colour and slap it on the next episode as soon as you can.” And so, we have this for the remainder of the series. Starting with a new explosion shot in colour with some colourful liquid thrown in for good measure, we transition into new APF and Videocolor logos rendered in the brightest red and gold available, and then an almost (but not quite) identical shot of Commander Shore taken from a slightly different angle and using a noticeably different copy of the Shore puppet to the one seen in the pilot. Call me old fashioned, but I much prefer the original black and white version of this opening moment, but probably for very basic reasons like the fact it was used on more episodes and therefore feels more familiar. Of course, let’s not forget the peasants at home still watching in black and white who would have barely noticed any difference.



This quiet, unnerving, nighttime scene sets the tone for the episode straight away. The boat is the same one used by Admiral Denver in Loch Ness Monster, as is the fishing rod. The SOS distress beacon is borrowed straight from last week’s episode, An Echo of Danger. Thompson, the craft’s single occupant, is revealed to be somewhat… ummm… unwell. His dead-eyed stare is really very effective. It just goes to show how much life is injected into the regular puppets who are also stuck with a fixed facial expression and eyes which are almost always open.

Shore picks up the emergency signal in the Marineville control room. The small handheld microphone which was added to the set for Phones’ call with X20 in An Echo of Danger is still present.

Because it really couldn’t be anyone else, Troy and Phones are the ones who are called upon to answer the call. It’s just another day at the WASPs. All very standard stuff. Not an ounce of humour or lightness of touch in the dialogue. Just enough to get on with the job and the plot.

Stingray surfaces next to the fishing boat. Goodness me these ocean shots in the moonlight look pretty. Incidentally, I think that’s a different moon to the one seen in The Ghost of the Sea.

A better look at the puppet-sized boat reveals that certain details on the prop have been stripped out compared to how we see it in Loch Ness Monster, such as the wooden panel on the front of the boat which has been completely removed.

Troy and Phones make their initial appraisal of the situation and conclude that the boat’s occupant is sick. I mean… let’s be honest, my first assumption would very much be that he’s dead. Stone cold dead. Might as well chuck him in the ocean and call it a day. But no, let’s just say he’s poorly and needs some medicine to perk him up a bit.

For the first time we get to see the outside of the Marineville Hospital. It’s another 1960s bit of brutalist architecture which you could probably find on any university campus built at that time.

Our cheery doctor from The Master Plan is back and this time he’s plugged Thompson into the mains. In fact, he’s wearing the brain electrocuting crown that Marina was forced into during the torture scene of Emergency Marineville. Apparently the WASPs are now using the device for medical treatment. The equipment that the Doc is staring at was previously the hydroprobe in Marineville Traitor.

While the Doc explains that he basically has no idea what’s wrong with the man, I’m much more distracted by Thompson’s enormous feet. They are huge.

So while Thompson is kept under observation, it’s time for Troy and Phones to get back to work, while Marina enjoys some time off… again. Don’t worry, they aren’t just trying to boot her out of the episode this time around.



A completely different establishing shot of the Marineville apartment buildings is used to the norm, which makes the Shores’ home appear to have changed locations compared to previous episodes. Marina and Atlanta are enjoying some music and civilised conversation. Atlanta is back in the stunning gold outfit she was sporting in Stand By For Action, while Marina has modified her usual dress by adding a skirt made of the same material El Hudat draped her in while she was kidnapped in Star of the East. The point of the conversation is basically to sum up for the audience that we know very little about Thompson, other than the fact his name is Thompson.

The Auto-Nurse on the wall above Thompson’s bed is later seen in the Tracy Island sick bay in the Thunderbirds episode, City of Fire. It monitors, or perhaps even adjusts, ‘Respiratory’, ‘Cardiac’, ‘Pulse’ and ‘Temperature’ apparently. If we zoom in really, really closely on the medical chart that the nurse is holding, it’s just about possible to make out the name ‘Thompson’ underlined in red at the top of the page, suggesting that this prop was made or adapted especially for this scene.

The popular theory is that this nurse is a heavily modified Marina puppet with some plasiticine additions to make her look a little more world-weary, while the nose and lips remain recognisable as Marina’s. It means that the eyes on this version have been swapped to brown instead of green, and a very 1960s blonde wig has been added. Like Marina, the nurse never speaks so it’s possible she was never fitted with the usual lip sync mechanism.




Thompson, maintaining his dead stare, begins to move. He interrupts the nurse’s reading by holding out his watch. This is David Elliott once again pursuing his passion for combining live action hand inserts with the puppets in the background, and I’m all for it. The watch begins to emit a high-pitched noise which is scary enough to make you wonder what’s going to happen next, but irritating enough to make you hope it stops making that noise as soon as possible. The nurse, unable or unwilling to ask any questions like, “What’s that?” or “What are you doing?” decides to silently accept her fate and fall flat on her face.

This is shaping up to be quite a grim episode.

Meanwhile, Marina has decided she’s had enough of Atlanta’s one-sided conversation for one night and wants to leave. It must be nice for Marina to be able to sneak away from crowded parties without having to go around saying goodbye to everyone in the room. It’s the one part of her life I’m envious of.

Apparently our friend the Doc is one of those cool people with no respect for furniture, as he casually parks his backside on the main control panel. As ever, he’s full of the joys of spring as Doc informs Shore that Thompson’s condition, whatever the heck it is, appears to have infected the nurse. Doc is urged to stay away from the patient and stop the mystery virus from spreading. Okay, one does have to suspend one’s disbelief for a little bit here because the idea that a fully qualified doctor would mistake a hypnotic trance, albeit an alien-induced one, for a contagious illness with no other symptoms is a tad difficult to take seriously. All the same, I enjoy the dynamic of Commander Shore impatiently bossing Doc around. He’s the closest character that Stingray has to the regular boffin-type that Supercar, Fireball XL5, and Thunderbirds had, but because Shore and the others really have very little time to listen to experts, the character is barely given any screen time or even a name. Doc was obviously a person that Alan Fennell was interested in developing further, but for some reason he was never given anything else important to do after this episode.




Thompson is out of bed, and opens his blinds completely unseen by the camera. It’s the return of those lovely one-third scale venetian blinds that I was a bit obsessed with in Hostages of the Deep. From the window, we have a glorious view of Marineville. That photographic blow-up sure does get a lot of use throughout the series. On his way to pick up the night shift, Lt. Fisher is eagerly driving to work with the motivation of an early coffee in the Marineville Diner. Atlanta’s review of the food in said diner in The Man From The Navy was less than flattering but it’s nice to know that the coffee’s worth getting up early for at least. It’s a treat for us to see another new part of Marineville. Okay, it’s just a street with an excessive amount of lampposts, but it just adds to the idea that Marineville is bigger than just the main tower and the apartment blocks.



Thompson remains unseen, but the hypnotic noise of his watch is activated and quickly takes effect on Fisher. That thing must have some incredible range! The lieutenant passes out and crashes his lovely little motor into one of those lampposts. I told you there were too many of them. The building he’s crashed in front of is the exterior of Stage 2 from Stand By For Action. The model of the car is the same one driven by Troy in The Man From The Navy.

Climbing back into bed, it’s looking like another point scored for Thompson.

The puppet-sized car doesn’t quite match the model, in that it has no wheels, but it’s the same prop used for the puppet close-ups of Troy’s car in The Man From The Navy, X20’s car in Stand By For Action, and Steve Zodiac’s car in various episodes of Fireball XL5. Fisher ain’t looking too good with some cuts and bruises to his face, plus the dead eyed stare of the trance. It’s rather lucky that the trance involves the puppets’ eyes remaining open since I don’t believe Fisher had an alternative blinker head made, unlike the rest of the regular terrainean cast.

Doc is back at the tower again to report that Fisher is not injured (despite what the cuts and bruises in the previous scene would have us believe), but he is in the same condition as Thompson and the nurse. Poor Doc must be exhausted running back and forth between the control room and the hospital every time someone passes out.

Atlanta is sleeping peacefully, her bedroom having only seen a few minor modifications since it last appeared in Marineville Traitor. The rug under the bed is much smaller and a few knick knacks by the window are missing.

Looks like she has a visitor. I bet it’s Troy, unable to keep it in his pants.

Never mind, it’s just creepy Thompson who has somehow managed to escape from the hospital, and is merrily wandering about through the Marineville to find his next victim. Have I mentioned that the WASP security team are rubbish? I also appreciate the attention to detail which has gone into matching the live action door used for close-ups to the door on the puppet set. That said, the puppet door is missing the important feature of a latch on the side.

More of that live action/puppet combo goodness. If you stare at this shot for too long, it does look like Thompson is an 18 foot giant looming over Atlanta, but for a quick cutaway it works well.

Atlanta passes out just before quite an early commercial break. The little red poodle on the bedside table watches her blankly. But now things are getting serious. Thompson appears to be unstoppable and we don’t even know why he’s doing any of this. Lots of mystery and suspense to keep us going!

Yup, Doc has gone back to the tower again. This time, he has to deliver the news that Shore’s own daughter has been struck by the virus. There’s a real sense that the situation is becoming increasingly hopeless, with no new answers coming in about what’s causing all of these comas.




The power plant goes offline, knocking out all the lights. The assumption is that everyone working over there must have passed out too… which doesn’t really explain how the lights went out unless they were manually shovelling coal into a furnace to keep the generators running. Shore calls upon the trusty tracking station, and David Graham is tasked with voicing several very similar characters in the same scene. The commander then reaches out to someone at H.Q. for as much assistance as they can offer. Apparently Shore needs the tracking station to set up a routine call back to H.Q. every four hours because he sure as heck can’t arrange that himself. But unfortunately, the tracking station chap is now failing respond. Someone should probably rush along there quick and catch Thompson in the act. Oh never mind, that would end the episode too soon.


The set for Atlanta’s hospital room is the same as Thompson’s room but mirrored. Her big pink nightgown from Loch Ness Monster is hanging on the door. She is still very knocked out. Meanwhile, Thompson has briefly returned to his bed so that we can have yet another one of those terrifying moments where he sits up and stares at the camera with those horrible eyes. They’ve really succeeded in making this guy look like the sort of bloke who goes down to his shed on a Thursday night with a telescope and a good view of next-door’s bathroom window.

Doc is now busy doing something vaguely sciencey in his laboratory. Bits of apparatus from the B1 as seen in The Golden Sea have been re-used on this set, as are various pieces of chemistry equipment previously seen in Venus’ lab in Fireball XL5 among other locations. Presumably our cheerful doctor is examining a blood sample or something, and pouring various dangerous chemicals over it for a bit of a laugh.

Ugh, Thompson’s out of bed again. Somebody feed that guy some horse tranquilisers.

The watch goes “wweeeooowweeeeewooooowwweeeeewwooooooooooo” and you know the rest. Look, I know Thompson is supposed to be relentless, and part of the terror is in the fact he’s able to get away with the same trick over and over again, but it does mean most the episode is just the same sequence repeated ad nauseam. I’m not saying it’s boring, and David Elliott does everything he can to make these moments visually interesting, but it doesn’t exactly make for a complex narrative structure.

Doc ends up with his head in the sink, which is probably how he finishes a night out at the Blue Lagoon.

Uh oh, I wonder who might be next…

Shore is very upset that Marineville has been brought to its knees by this mysterious condition. I must say, Thompson has certainly worked quickly to knock out every single person in just one night.

I… he… how did… DID X20 LEAVE HIS WINDOW WASHING STUFF LYING AROUND LAST WEEK?

Shore gets knocked out, dramatically slamming his chair into forward gear and crashing into the camera for good measure. As I said, the direction for this episode is doing a very good job of making big moments out of fairly repetitive pieces of script.


Now I always thought this was supposed to be the Shores’ apartment, but apparently it’s Marina’s. Or have they been mixing it up all the way through the series? Anyway, Marina’s bedroom was last seen in Marineville Traitor and appears to be unchanged. She’s sleeping away quietly after that exhausting evening of listening to Atlanta talk about whatever it is Atlanta finds herself able to talk about.




Someone’s come for a visit and it’s not the Easter Bunny. But this time, Thompson is in trouble. His hypnosis fails to work on Marina who remains conscious and just watches the weirdo quietly toddle off. So this is a bit of a development! All of Marineville is knocked out and Marina is the only one who can repel Thompson’s attacks. Why? Who the heck knows, but it’s something!

Remember these two? Yeah Troy and Phones haven’t had a lot to do so far, but all that is about to change. They are completely unaware that anything has gone wrong at Marineville. I’m surprised Commander Shore didn’t let them know, but maybe he was busy, or just straight up didn’t want to talk to Troy which I would completely understand.


A tapping sound on the radio starts to irritate Captain Tempest, and it takes the thicky twins quite a while to figure out that it’s Marina trying to get in contact with the trusty old tapping code.

Troy finally learns a little of what’s been going on with a series of ‘yes’ and ‘no’ questions. It also serves as a nice reminder of the plot so far in case you’ve been struggling to keep up with all this.

And so, with very few proper details, it’s time for Troy and Phones to head back to Marineville and save the day. Wouldn’t it be nice for a change if Marina had it all squared away before they got back? That doesn’t happen, of course, because the series’ formula dictates at this point that Troy has to be the hero, and Marina is the damsel in distress.




Marina pays a visit to Atlanta in the hospital. There’s a grey and fury thing in the corner that looks suspiciously like Oink but, to be frank, he’s long gone by this point in the series. Thompson locks the door in the noisiest way possible by rattling the key around. Marina knocks and tries the handle but it’s no use – she’s trapped. Well, so much for her saving the day. I’m curious how Thompson, in his trance-like state, was able to find and identify the key to Atlanta’s room out of all the keys to all the hospital rooms. Sure, with some time and reasoning, he could probably figure it out but it would take some doing. Perhaps someone has more control over him than we initially realised.



Stingray returns to Marineville while Thompson returns to bed. Walking all the way around Marineville must be exhausting. Marina’s chair is missing from the Injector Bay, although that’s probably because it looks a bit crowded in there with it in place. Our two detectives notice that it’s dark and there’s nobody about. Great observations guys. It’s gonna be a long night.

While Marina continues to bang on the door of the hospital room, Troy and Phones have found the commander snoozing in the control room. Troy picks up on the fact that he’s in a trance but for some reason completely fails to connect the dots back to Thompson immediately. To Troy, Scotland Yard is somewhere they park trains.



Troy’s got himself a brand new car which could be mistaken for the Batmobile. They clearly identify the wreck as Lt. Fisher’s car even though everyone, including Troy, has had a go at driving it at some point in the series.



The security guards may appear to be in a trance, but it probably isn’t any different to how they normally look considering how sloppy their work is. Finally, Troy and Phones figure out that Thompson is involved and make the hospital their next port of call. They’ll probably stop for ice-cream first because, heck, why rush?



With her knuckles probably bleeding by this point from all that ruddy knocking, Marina is finally starting to get tired. Fortunately, Troy and Phones are trotting down the corridor and hear her. Even more fortunately, Thompson has just left the key in the lock for any idiot to come along and use.


Marina is absolutely thrilled to see her friends again. It doesn’t look like she’s thinking, “what took you so bleeding long?”



Troy attempts to get more information out of Marina. But, because he’s an impatient so-and-so, she has to prevent him from blundering off and trying to stop Thompson by himself. There’s a brief suggestion that Marina hasn’t succumbed to the hypnotic influence because she’s from under the sea, which is possibly where Thompson’s condition originated from. No more explanation is given, but it’s nice to have even a suggestion that Marina has abilities as yet untapped by the WASPs. For a puppet, Marina does a very good job of miming a watch, but the lads don’t pick up on it because by the time everyone plays charades at Christmas, Troy and Phones are usually passed out under the tree.

Well, as you might expect from Troy, his new plan involves putting his friend Phones in terrible danger by using him as bait. Phones couldn’t be less enthused, but he goes along with it anyway because that’s the sort of nice but foolish guy he is.




The cunning plan is to have Phones waltz up to Thompson and hope for the best. I kid, there’s more to it than that. It’s actually all very tense and beautifully shot. The lads are sweating with fear. And just when you think Thompson might not wake up, his eyes come to life and it’s time for him to start work again.

The watch is brought out. We’re still on the puppet set for this live action insert, but this time there are no puppets in the background. The forced perspective still works incredibly well. It’s 3 o’clock in the morning if the watch is anything close to accurate.

When Phones yells out, a live action double in an approximation of Troy’s uniform kicks the doors open and jumps in. The sound of a gunshot is heard but we don’t actually see the gun fire.

The watch is yanked out of Thompson’s hand by a wire which you can only see if you’re a sad act like me who slows the footage down.

It drops to the floor and breaks. Probably a cheap knock-off.

Thompson comes around, and immediately he looks much more friendly. The puppet moves a lot more now to indicate that his mind is his own again. It’s really an excellent performance by the puppeteer to get across the change in character just with movement.


Troy has the bedside manner of a Gestapo officer, and Thompson gets a headache just from looking at him.

Then it all becomes clear. As the lights come back on, they realise that everyone at Marineville was under the influence of the watch and has woken up now that it’s been broken. Thompson was under the same hypnosis, administered by someone from under the sea who interrupted his nice fishing holiday. Poor bloke. Hope he had travel insurance.

The alarm is sounding across the whole of Marineville. Someone probably left the gas on while they were in their trance.

Another whip pan transition which once again doesn’t really show us very much. That could be a lighting stand?

Up in the tower, a very tired Commander Shore is briefing Troy. An unidentifed craft is approaching Marineville, and suddenly the whole puzzle fits together. The villains’ plan was to knock everyone at Marineville out using the hypnosis, leaving the WASPs defenceless and open for an attack. Nice plan, but they should have checked whether Stingray was at home first.


Stingray is launched and Phones is on the case to track down the enemy sub. The pace of the episode is suddenly having to pick up so that we can tie up the loose ends with an exciting action sequence.

Recognise this fella? Yes all the footage of the enemy craft is lifted straight from The Ghost of the Sea. It isn’t mentioned, but it’s possible that the villain is the same “ghost” seen in that episode, having decided for some reason that he wants to destroy Marineville. I doubt that was the intention. The production team just didn’t want to shoot any new special effects sequences so used the most suitable stock footage available from another episode. To the casual viewer it’s perfectly acceptable, but any Stingray fans watching are bound to feel a little cheated.

Troy and Phones manage to dodge the enemy attack. I do wonder whether this action sequence was added purely for the sake of adding some action to an otherwise slower-paced episode. It just doesn’t quite seem to sit right in the rest of the story. Also, seeing as it’s made up entirely of existing footage, the sequence isn’t exactly memorable or unique.

Just as we saw in The Ghost of the Sea, the yellow sub is blown up. Supposedly a short production break was taken after Invisible Enemy was completed. Lew Grade had initially comissioned 26 episodes of Stingray before the run was extended to 39. I wonder if one of the impacts of that production break was a greatly reduced amount of time to spend on new effects shots for this particular episode. Pure speculation. In relation to the break, there is also a story of Don Mason and Robert Easton taking the extended commission of an additional 13 episodes as an opportunity to demand an increase in their fee, having learned that veteran Anderson voice artist David Graham was earning more than them.


So I guess there’s a parallel universe out there where Invisible Enemy is the final episode of Stingray, or Troy and Phones might have come back in the next episode with different voices. I don’t think either of those two eventualities were particularly likely, but it’s fun to imagine what could have been. Presumably, the slightly revamped opening titles we discussed earlier were produced for the final batch of 13 additional episodes, but were used on this episode because the new shots happened to be ready early. I’m also guessing the production break offered additional time to get scripts ready for the next few episodes. Alan Fennell seems to have been doing the lion’s share of the writing for the past several weeks which must have been a strain. Did Dennis Spooner have other commitments, such as his comedy work with Tony Hancock?

In order to avoid him looking like the undead, Thompson has received a new paint job. He’s certainly looking a lot healthier now. And that blue jumper he’s wearing feels very familiar. It took me a moment to figure it out but a quick glance at Virgil’s outfit in the Thunderbirds episode Edge of Impact brought it all back to me. I’m fairly sure Commander Shore wears it in a later episode too.

Apparently, Thompson gets to have the honour of having coffee with the Marineville gang. He’s a nice guy really. Not the sort of fella who would really want to try and wipe out an entire top security base to help an undersea race conquer the land. But more importantly, Fisher has been invited over to the Shores’ apartment for the first time since the pilot episode. He must really be getting into their good books now.


To show his gratitude to Marina, Troy, and Phones for saving the day, Shore grants them all a short vacation to, “have a ball.” That’s code for, “get plastered in Magaluf and dance on the bar of the club until the bouncers throw you out for indecency.”

But when the commander offers to pay for this extravagant trip, Atlanta makes a side-splitting gag about how her father must be stuck in his trance still. Someone fetch a sedative, I’m going to laugh myself into a heart attack.
Invisible Enemy is another re-invention of the wheel for Stingray. David Elliott rose to the challenge of directing this story superbly, pulling out all the stops to get the tone just right. His use of lighting and live action inserts creates a surreal, unsettling atmosphere which serve to make the hypnotised Thompson into a credible threat. A man standing at a door holding his watch becomes an exciting and dramatic moment with serious consequences. All of the major characters are given some time in the spotlight this week, at the expense of us not seeing much of Stingray itself or many special effects shots. The episode also doesn’t show us any underwater aliens apart from a few quick glances at their craft via recycled footage. The whole point of Invisible Enemy is to challenge the Marineville team with a different kind of threat. So fans of the standard Stingray format may be disappointed by this story and not rate it too highly. But, for others, Inivisble Enemy is something of a hidden gem. It offers an unnerving tale which sees our heroes stumped and utterly powerless against a force they can’t understand, and that’s quite exciting. But don’t have bad dreams the next time someone comes knocking at your door in the middle of the night…
Next week, the Stingray crew are in for some serious heat, and it’s seriously deep. We’re talking about an undersea volcano with a subterranean civilisation living beneath it who are desperate for freedom. It’s Deep Heat…
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Further Reading
www.filmedinsupermarionation.com by Century 21 Films Ltd.
Filmed In Supermarionation by Stephen La Rivière. Third edition published in 2022 by Century 21 Films Ltd.
Stingray: Adventures In Videcolor by Andrew Pixley. First published in 2022 by Network Distributing.
I have gorwn more and more fond pf this episde as the years have gone by. I think it’s probably because of the eerie plot and setting,etc. I never noticed that Commander Shore’s puppet from was a new version from this point onwards either. As for that nurse, to me she always looks a bit like someone who has been drinking a bit too heavily.
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