Directed by Vere Lorrimer.
Airdate: 27 March 1978.
Following on from the previous episode Blake is determined to deliver the medical supplies to Ensor, his mission made more urgent by the fact that everyone who was on Cephlon has radiation poisoning. He is unaware that Servalan and Travis are also on the planet, planning to take Orac for themselves.
This episode has the following tropes:
- Absurdly-Spacious Sewer: Justified as they are implied to be normal corridors in a city that has now sunk below the ocean.
- Accidental Aiming Skills: Avon saves Blake's life by shooting out Travis' gun hand from a considerable distance. When Blake compliments him on the shot, Avon bitterly replies that "I was aiming for his head". Rumour has it that this was an ad lib by Paul Darrow, who's rather fond of Westerns and couldn't resist the Shout-Out.
- Artificial Intelligence: Orac
- Auto-Doc: With the Space Surgeon killed in the previous episode, Blake decides to take Ensor up to the Liberator where there's a fully equipped surgical unit and Orac can advise them how to do the operation.
- BBC Quarry: Springwell Lock Quarry in Berkshire, plus Stock Footage of the ocean, doubles as the surface of Aristo.
- Big Damn Heroes:
- Travis (and Blake) intervene to save Servalan (and Cally) from the amphibian monsters.
- Avon realises that something has gone wrong, and teleports down with Vila Just in Time to save Blake's life.
- Blasting It Out of Their Hands: Avon shoots Travis' Arm Cannon before he can shoot Blake. Unfortunately, Avon was aiming for his head.
- Bond Villain Stupidity: When Servalan stops Travis from shooting Blake he snaps, "No! I've waited too long!" After some Evil Gloating on her part she does give Travis the go-ahead, but as usual this is just enough time for Avon to intervene.
- Butt-Monkey: Vila bangs his head on a door and teleports into a puddle.
- Captain's Log: Blake uses a Flight Log entry to fill in Avon and the audience on the previous episode's events. We never see any reference to this trope again, which is just as well because a Rebel Leader keeping a record of his activities would be a major Idiot Ball if the Liberator were captured, which it is on several occasions.
- Chekhov's Gun: There's a closeup of the hatch through which Travis and Servalan later make an explosive entry.
- Cliffhanger: Orac claims that it can predict the future, and produces an image of the Liberator being destroyed.
- Computer Voice: Orac has the voice (and irascible personality) of its creator.
- Cruel Mercy: Travis tells Blake to Get It Over With. The others are only too glad to comply, but Blake stops them and says he'll send the Federation a message that Travis and Servalan let them escape with Orac.
- Dirt Forcefield: Servalan's pristine white outfit is impervious to her crawling through muddy tunnels.
- Dungeon Bypass: Servalan and Travis get past the force barrier protecting Ensor's base by going through some underground tunnels and blasting their way through a hatch.
- Dying Alone: Gan and Jenna end up hanging out with Avon in the teleport room so they won't die alone. Vila prefers to remain in denial, so he stays by himself.
- Electronic Speech Impediment: Zen as Orac takes control of the Liberator.
- Explosions in Space: The explosion of the Spacemaster produces a cloud of smoke that rises upwards, despite being in a zero-gravity vacuum.
- Filming for Easy Dub: Stephen Greif was out sick with a hand injury when it was time to shoot the studio scenes, so they had a stand-in, only seen from below the neck or behind a tank of murky white liquid, then had Greif loop the dialogue later.
- Forced Perspective: The tubular lift breaking through the sand.
- Ghost Planet: Aristo's population is long gone with their ruins sinking below the ever-expanding oceans. An amphibian form of life is evolving in their place.
- Grumpy Old Man: Ensor, with some Absent-Minded Professor as well.
- Immediate Self-Contradiction: Orac says that their relationship "will be best served if your statements are free of ambiguity". But when pressed for when the Liberator is due to be destroyed:Blake: When's this supposed to happen?
Orac: The event is not far distant.
Blake: How far distant?
Gan: There must be some way of making him tell us when.
Avon: Be more precise.
Orac: The event is now even less distant.
- Improbable Aiming Skills: Avon shoots off Travis' arm.Blake: Good shot, Avon.
Avon: I was aiming for his head.
- Just Think of the Potential!: Orac has the ability to access tarial cells, a basic component in all computers in all the known worlds, potentially accessing the sum of all knowledge. As such it boasts that its limitations have not yet been defined.
- Layman's Terms:Vila: I think I've heard enough. I don't like him. Orac, be a good junk heap - shut up.
Cally: I agree with Vila.
Orac: Define the words 'Shut up'.
Blake: Stop talking. Do not speak. Be silent.
Orac: That is better. Our relationship will be best served if your statements are free of ambiguity.
- Lizard Folk: The Phibians which are evolving into the next dominant species on the planet.
- Magical Security Cam: The flight log recap includes scenes from the previous episode that Zen could not have recorded.
- Man in a Rubber Suit: When Phibians attack!
- Meaningful Name: Orac is an oracle.
- Never Split the Party: On arriving at a divided corridor, Cally asks if they should split up to search for Ensor, but Blake points out they'd likely end up searching for each other.
- Nice Job Fixing It, Villain: Servalan's desire to get sole credit for finding Orac means that Blake's rebels now have the most powerful computer in the galaxy.
- Non-Action Big Bad: Servalan isn't even carrying a gun, relying on Travis for protection.
- Obscured Special Effects: The Phibians were originally operated by two people, but the result looked like a Pantomime Animal. Even a single operator version resembled People in Rubber Suits, so they were instead portrayed via short cuts, clawing hands and creepy shadows.
- Our Doors Are Different: A tube elevator rises from the sand on the beach to take Blake and Cally to Ensor's Elaborate Underground Base.
- Percussive Maintenance: Suggested by Vila to get a response from Orac ("Try kicking it").
- Phlebotinum Pills: Avon says not to worry as they can just take a heavy dose of decontamination drugs. But the Liberator doesn't have any on board, and their only hope is that Ensor might have some.
- Plot-Driven Breakdown: The excessively-overstocked Liberator doesn't have anti-radiation drugs, which should be standard for any spacecraft.
- Plot Hole: The reason Orac is so effective is that it can access the tarial cells which are a basic component of all computers in the Federation. This doesn't explain how it was able to control an alien-built computer like Zen, unless they use a similar component.
- Previously on : Blake plays his Captain's Log to fill Avon in on what happened with Ensor Jr.
- Roar Before Beating: The Phibians give plenty of roars to let potential prey know they are coming.
- The Scapegoat: Blake is going to tip off the Federation about how Servalan stuffed up. Her response? "You're in a lot of trouble, Travis."
- Screaming Woman: Servalan shrieks in terror when a Phibian grabs hold of her. Travis returns to kill it, and offers to lead the way through the narrow tunnel. But Servalan quickly regains her dignity and announces that she will lead and Travis will follow!
- Season Finale
- Seers: Orac can gather information and extrapolate from it, giving him the ability to predict the future.
- Self-Plagiarism: Terry Nation reuses the heroes getting radiation posioning and the search for an antidote plot from Doctor Who's "The Daleks".
- "Shaggy Dog" Story: Ensor dies just a short distance from the exit.
- Shout-Out: Paul Darrow was a fan of The Western, hence the "I was aiming for his head" line from The Magnificent Seven.
- Sinister Silhouettes: Just before a Phibian attacks Cally.
- Some Kind Of Forcefield: The force barrier on the beach is only visible when Blake and Cally try and touch it.
- Talking to Plants: Ensor talks to his plants as well as his pet fish. Given that Orac has taken on aspects of his creator's personality, it makes one wonder if the Artificial Intelligence doesn't regard the crew of the Liberator in a similar fashion.
- Thanks for the Mammary: Jan Chappell does this to Sally Knyvette (in the scene where Cally helps a sick Jenna to her cabin) and has to hastily reposition her hand.
- Vomit Discretion Shot: Suffering from radiation sickness, Vila runs off to throw up.
- You Talk Too Much!: Moments after turning Orac on, the crew are begging Blake to shut him off.