[2] It is 342 days after leaving Earth orbit, and Moonbase Alpha is recovering after a recent encounter with a space warp.
Commander John Koenig dispatches a survey Eagle to reconnoitre a nearby solar system for the rare mineral.
Computer analysis reveals large deposits of titanium, and Astronauts Bill Fraser and Ray Torens are recalled.
Tony Verdeschi, head of Security and recently appointed second-in-command, mobilises the defences—which now include large-scale laser batteries.
Koenig immediately accuses the being of attacking an unarmed survey ship—which, Mentor counters, was trespassing on his planet.
In the interests of peace, the alien will also give them the titanium, asking that a science specialist be sent to discuss the details.
The girl is a metamorph, trained by her father in the Psychon art of molecular transformation, able to assume the form of any living organism at will.
When full engine thrust fails to break the alien's grip, Koenig orders the booster rockets fired.
The alien scientist touches a panel and Torens arches in agony, mouth opening in a silent scream.
Picard spies titanium ore among the loose gravel littering the ground; Helena pockets the nuggets to take back to Alpha.
Hoping to overpower the barrier, Picard fires his laser rifle—but the beam ricochets back to atomise the Frenchman.
The room is dominated by a surreal artefact: a hexagonal dais from which dozens of glass conduits rise to penetrate the rocky ceiling.
The conduits contain bubbling organic fluids of every colour, and the object hums and pulses with energy.
Using its ability to manipulate matter, he plans to transform this dying world from a volcanic wasteland back to its former splendour.
The alien scientist makes a gruesome revelation: Psyche derives its energy from the minds of intelligent beings.
Koenig is appalled as the madman states the arrival of the Moon and its 297 human inhabitants should provide enough energy to make his world live again.
When Koenig refuses to hand over the Alpha people, Mentor demonstrates his power by detonating a lunar mountain close to Moonbase.
Asking Verdeschi in private, she is told it is a code signal between Koenig and himself—an irrevocable order to destroy the place from which it is issued.
To her horror, the security chief contacts the Weapons Section and orders a remote-controlled Eagle equipped with a maximum load of nuclear ordnance.
Verdeschi tries to convey the severity of the situation, but the hysterical Annette, thinking only of her husband, refuses to listen.
Mentor grabs him, shouting that the sudden release of Pyche's energy could destroy the planet; Koenig throws off the older man and continues his vandalism.
In the caves, Helena and Fraser try to retrieve Torens, but the pilot is buried alive when the ceiling collapses on the unfortunate miners.
As Wadsworth's modern style, with its strong beat, would complement the new Space: 1999's action-adventure format, he was chosen as the composer for the second series.
[3] In October 1975, in the midst of pre-production on its second series, Sir Lew Grade informed executive producer Gerry Anderson that Space: 1999 would be cancelled unless extensive changes in form and content were made.
The show would become more action-oriented and present a dynamic new cast of younger regulars joining Martin Landau and Barbara Bain.
Freiberger had judged the first-series' supporting cast to be 'unlikeable'; considered expendable, he made no attempt to explain their absence.
Many attribute this continuity breach to Freiberger as, purportedly, the producer had screened only eight first-series episodes after joining the production.
[5] The term tiranium would be used in the subsequent episode "Catacombs of the Moon", also as a rare and vital mineral essential to the life-support system.
The script's multiple revisions may have confused the author: Tony Verdeschi is left in command of Alpha while Simon Hays accompanies Koenig to Psychon.
In the 2003 novel The Forsaken written by John Kenneth Muir, it is stated the events of this story were one of the consequences of the death of the eponymous intelligence depicted in "Space Brain".