The Gathering Horror is the eighth episode of the second series of the classic BBC science fiction TV series, The Phenomenon Effect. Often considered the high point of season two, The Gathering Horror introduces the character of Lt. Pringles, and the departure of Prof. Inga Hotchickinglasses, and is also the first episode to feature Agent Wib's famous "space pencil". It is also fondly remembered by Phenomenon Effect fandom for Wib's "crushed by a submarine" speech, and for the tragic death of the beloved Lt. Pringles.
According to an interview in The 'Nom: The Phenomenon Effect Magazine, writer Kerry Slythe was commissioned to write the script after legendary  Phenomenon producer Terry Ling saw a production of one of his previous scripts. Entitled Colgate Toothpaste and Why You Should Use It, this thirty second production was generally ignored by critics but frequently repeated nonetheless.
“...it was a Monday, I think, and I was hard at work when Terry [Ling the legendary producer of the best show ever] came up and dropped fifty pence in my violin case. Then he commissioned me to write an episode of [The] Phenomenon [Effect]. I asked what sort of story he wanted and he shrugged and said he had no idea, he never watched the show, but he'd pay me extra if I also did the incidental music”
Importantly, this episode featured the introduction of something that would become one of the most famous aspects of the show - Agent Vib's famous space pencil. Speaking at a panel at EffectCon '87, Sylthe described the origin of the pencil:
“The space pencil... yeah, the space pencil... uh... I hate to bring this up but... there was mention of a buffet?”
The script had to be written in a hurry in order to meet the grueling schedule of The Phenomenon Effect in which an entire thirteen week season was often shot in under a month. In order to write the episode in the eight hours he had been alloted, Slythe was obliged to get some additional dialog from his landlord, Yoltan Verbascof, which resulted in the characters of General Wittershaw and Colonel McTavish speaking all of their lines in Croatian. This was explained in the script with a line from Prof. Hotchickinglasses, who says that an "alien germ virus" had attacked the "talking centres of their cerebrums" during a recent visit to Belgrade.
The highlight of the script was of course the legendary "submarine" speech, of which Slythe said
“In the submarine speech, I really wanted to encapsulate that sense of uncertainty that is at the heart of the Human Condition. Why are we here? What purpose do we serve? Why am I, a busker, frequently commissioned to write television scripts? I mean, it's pretty unlikely when you get right down to it.”
Following the scrawling of the first draft, the script was put into production under fan-fave  Phenomenon Effect director, Barry Slugg. According to an interview in the Phenomenon Effect fanzine Countdown to Minus Five, Slugg saw the script as "challenging", "technically demanding" and "one more step on my long downward arc from promising drama student to doomed, defeated alcoholic hack". With his characteristic self depreciating humour, he said
“The Gathering Horror was a milestone for me; it was the first episode that whiskey alone couldn't get me through. That's when I started on the amphetamines. I'd have preferred cocaine, but I just couldn't afford it on what [famous and talented producer] Terry [Ling] was paying me.”
The production of The Gathering Horror was plagued by problems. Start of filming was delayed for a day by what was erroneously considered strike action. In fact, a large part of the technical staff were members of the Strike Reenactment Guild, an organisation dedicated to creating period costumes and placards and recreating famous strikes from British history.
The episode was shown on ABC TV in Australia on 3rd May 1977, and repeated over five hundred times over the next ten years, before being replaced in the schedule by repeats of Grange Hill.
In the US, as per the usual policy of American TV networks, CIA agents keept watch on every Phenomenon Effect fan in the country. Their reports were used to schedule a time when none of them would be able to watch it, 11.15pm EST, 11th December 1978.
Following the disastrous events of The Multiplicand Quotient, the agents of Space Organisation Beta are in disarray. Prof. Hotchickinglasses brings them all nice hot cups of space tea to cheer them up, but they are further confused by the sudden arrival of the officers, who are only able to speak Croatian, due to a virus contacted in glorious empire of Greater Croatia!
All hail Greater Croatia! 
Meanwhile, on the Grendulon Planetsphere, King Grendle is plotting another attempt to take over the Earth Empire, this time by hiring the 'space mercinary' Zimbel the Assassin to murder Earth President Tokenwoman . Zimbel infiltrates the Presidential Office by posing as a Telex repairman. He is recognised by Lt. Pringles, who phones Space Organisation Beta. Zimbel realises his plan, and shoots him while the space operator is trying to connect him.
Back at Space Organisation Beta headquaters, Agent Wib is discussing submarines with General Wittershaw, when the phone rings, and Wib and Wittershaw hear the sounds of Pringles dying on the other end. Wib calls the space operator, who traces the call back to the Presidential Office. At this point, Zimbel cuts telephone lines to the Presidential office, and begins assembling a sniper rifle.
Space Organisation Beta springs into action, teleporting to the President's Office using their teleportation hats. Once there, the Earth President refuses to be evacuated, saying that if an assassin could make her leave her office, then there would never again be any hope for mankind.
While this discussion goes on, Zimbel hides in the president's cupboard, staring out through the slats, and waiting for a clear shot. As the President's aide suddenly transforms into a gorilla and begins fighting with Agent Wib, Zimbel sees his chance and fires. His face contorts with pain, and he looks down and sees a bullet hole in his chest. Outside in the office, we see two cupboard burst open as bodies fall out of them.
Back at Space Organisation Beta HQ, Agent Wib explains that as insurance for his grand plan, King Grendel had secretly had Zimbel cloned, reasoning that if one assassin failed, the other might succeed. However, this overkill had doomed his plan, as both assassins had picked diametrically opposing cupboards, and shot one another.
Then Prof. Hotchickinglasses announces that she will be marrying the real telex repairman.
- Earth President: Is my Space Telex still broken? How am I to telex the far flung reaches of the Earth Empire?
- Aide: You could use the space telegram, ma'am?
- Earth President: How primitive! Oh, well, fire up the atomic typewriter and take a letter.
- Wib: Imagine, if you will a submarine. Now this submarine represents everything we know - everything. It is the sum total of human knowledge. But beyond it, ah, beyond that little bubble of air, bound in steel and powered by twin diesel engines... Well, what is there? Does anyone truly know? Can any submariner truly know the nature of the salty fluid that surrounds them? After all, they can't open a window; nor a door for that matter, for they would be crushed, crushed by a submarine. So how could Nemo himself know the nature of the ocean?
- Gen. Wittershaw: Sbri'pol ek tui vr'plip?
- Wib: Actually, no, I have never heard of a periscope. What is... Oh, is that the phone?
- Earth President: But if an assassin could make me leave this office, then what hope has mankind? If I allow a maniac with a high powered rifle aimed directly between my eyes to tell me what to do, the next thing you know people would be intimidated by criminals brandishing guns and knives! What next, children giving their lunch money to avoid being punched?
- Col. McTarvish: Mydeme Presidenskys, vrol pro klungl vyeri splinechna. Va sordan plil? Sordan plil ya svorgant? O kjil prenb? O kjil driv? Co, co frint sdyjecta?
- Earth President: My answer is still no!
- Cadet Jones: But why are you leaving? You are our top scientist and engineer. And you make a fine cup of tea, what's more.
- Prof. Hotchicinglasses: I know. But within the last ten minutes I've fallen in love, so I must give up my career to marry him.
- Cadet Jones: Wow. That was arbitrary.
- Prof. Hotchicinglasses: (barely audible) Don't ad lib, you little Welsh git.
- Fred Burnely: What's that?
- Agent Wib: Space pencil.
- Fred Burnely: Where did you get it?
- Agent Wib: Stationary room.
- The sound of the "space chainsaw" was produced by electronically "mixing" the sound of an ordinary chainsaw with Richard Strauss' tone poem Also sprach Zarathustra.
- Gerry Ottwell, who played Zimbel the Assassin also played Zorgo the Assassin in the Doctor Who storyline "The Evil of the Planet of Terror"; Anaxin the Murderous in Blake's Seven; Zircon the Hired Killer in Sapphire and Steel, and Assassino the Murderous Assassin Who Kills People... To Death! in The Avengers.
- The episode has been praised  for it's haunting yet strangely jaunty background music, composed, scored for one-man-band and played by Kerry Slythe, who also wrote the episode.
- Actor Marcus Pliesy plays the third black character to appear in the series. Coincidentally, in series seven his brother William Pliesy would play the tenth black character to appear in the series, and the first to survive until the end of the episode.
- The Earth President's Office was seen in three episodes prior to this one and in eight episodes after it. No cupboards are visible in any of these other episodes.
- The reason that the President's aide turned into a gorilla would not be revealed until seventh season episode Retcon and Eggs
- ^ This line has been highly controversial amongst Phenomenon fans, as Belgrade is in Serbia. Some fans believe that the Professor was confused and meant Zagreb, whilst others point out that by the 'Nomeverse of the 23rd century Serbia would probably have been absorbed into the Greater Croatian Empire.
- ^ The Gathering Horror.
- ^ Another example of The Phenomenon Effect being ahead of its time. In the real world, it wasn't until 1989 that the first woman was elected President of Earth.