Production Code: 4H
1 - 27/09/1975 17:45
2 - 04/10/1975 17:45
3 - 11/10/1975 18:05
4 - 18/10/1975 17:45
The TARDIS picks up a distress call and the Doctor and Sarah arrive on the planet Zeta Minor. There they discover that a Morestran geological expedition has fallen prey to an unseen killer and only the leader, Professor Sorenson, remains alive. A
military mission from Morestra has also arrived to investigate. The culprit is revealed to be a creature from a universe of antimatter, retaliating for the removal by Sorenson of some antimatter samples from around the pit that acts as an interface between the two universes.
The Morestrans take off in their ship, but it is slowly dragged back towards the planet due to the antimatter on board. Sorenson himself becomes infected by antimatter and gradually transforms into antiman, a monster capable of draining the life from others.
The Morestran commander, the increasingly unhinged Salamar, attacks Sorenson with a radiation source but this only causes him to multiply, and soon the ship is overrun by deadly creatures.
The Doctor finds the original Sorenson, takes him back to the planet in the TARDIS and throws both him and his samples into the pit, fulfilling a bargain he earlier made with the antimatter creature. Sorenson reappears unharmed and the Doctor returns him to the Morestran ship, which is now freed of the planet's influence.
The shimmering red outline of a huge creature looms over the Doctor and Sarah. Sarah tries to get away but falls to the ground, and the creature advances toward them.
The Doctor arrives at the black pit leading to the universe of antimatter. As Sarah watches from the bridge of the Morestran ship, the events being relayed there via an oculoid tracking device, the antimatter creature emerges from the pit and the Doctor is dragged forward and topples over the edge.
The Doctor and Sarah are restrained in pallets in the Morestran ship to be ejected into space. The outer hatch opens and Salamar orders his deputy, Vishinsky, to activate the ejection switch. Vishinsky refuses, and a struggle ensues in which Salamar pushes the older man's arm down onto the switch. The pallets slide forward and through an inner hatch.
The Doctor and Sarah leave to keep an appointment with the Brigadier, and the TARDIS spins away through space and time.
The Strange Case of Dr Jekyll and Mr Hyde.
The Quatermass Experiment.
It! The Terror from Beyond Space.
Star Trek's 'The Alternative Factor'.
There are two quotations from Shakespeare ('Night's candles are burnt out...' (Romeo and Juliet) and 'That is the question'), and an allusion to Laurence Oates ('I'm going out now, and I may be some time').
The Doctor : "Here on Zeta Minor is the boundary between existence as you know it and the other universe which you just don't understand. From the beginning of time it has existed side by side with the known universe. Each is the antithesis of the other. You call it "nothing", a word to cover ignorance. And centuries ago scientists invented another word for it. "Antimatter", they called it. And you, by coming here, have crossed the boundary into that other universe to plunder it. Dangerous..."
The Doctor : [To Sorenson] "You and I are scientists, Professor. We buy our privilege to experiment at the cost of total responsibility."
"If you don't come now I shall have to leave you."
The time rotor is an instrument on the TARDIS console, the central feature of which is the time column (see The Chase). The Doctor implies that he is unable to tell where they have landed from the TARDIS' instrumentation, sending Sarah back to the TARDIS for his spectrum mixer, with which he will fix their spatial position via the position of the stars (see The Daleks, Frontier in Space).
According to the Morestrans, Zeta Minor is beyond Cygnus A [which can't be a reference to Cygnus within the Milky Way], as distant from the Artoro galaxy as that is from the Anterides. Despite the hugely inaccurate first landing, the Doctor can execute two perfect short range trips (from the Morestran ship to the pool and back to the ship again).
Morestran technology is advanced enough to allow the TARDIS to be 'transposed' back to their ship, but other aspects are unremarkable. Reference is made to Galactic Mission Control [but it is impossible to establish the nature of this body, or the relationship of Morestra to it]. The 'home planet' is also mentioned [it seems likely this refers to an originating Earth colony rather than Earth itself].
Dialogue indicates that many civilisations are facing disaster, including Morestra, whose sun is dying. Sorenson is hoping to extract a new form of energy from the rocks of Zeta Minor. (The Doctor suggests that they think of harnessing the kinetic force of planetary movement instead.) Morestrans have a number of religions or denominations: Morelli was Morestran Orthodox. Their unit of acceleration is STS.
Zeta Minor, c. 37166.
The Doctor met Shakespeare once (cf. City of Death), and describes him as a 'charming fellow... Dreadful actor.'
The TARDIS control room appears for the first time since season eleven's Death to the Daleks. This slightly redesigned set was first used for Pyramids of Mars, which preceded Planet of Evil in production order.
Frederick Jaeger and Ewen Solon, appearing in this story as Sorenson and Vishinsky, had previously played Jano and Chal in season three's The Savages.
There is a dramatic freeze-frame cliffhanger at the end of Part Two.
'You've reached the point where your tissues are so monstrously hybridized that the next metabolic change could be the final one.' (Actually, this makes sense, but it is noted here as Clive James referred to this line in The Crystal Bucket.)
The TARDIS central column vibrates alarmingly throughout, and the Police Box light carries on flashing long after it has landed.
The camera wobbles when Salamar is talking to Sorenson in the third episode.
The resolution to the cliffhanger at the beginning of episode four is a bit suspect, as the Doctor and Sarah were much further down the ejection 'tubes' when last seen in the third episode.
Sarah knows an awful lot about Morestran ship design.
Sorenson's glowing eyes are clearly 'painted' onto his eyelids.
The 'plaque' on the Force Field Equipment door flaps like a piece of cardboard.
Tom Baker almost falls over after throwing Sorenson and the container of anti-matter down into the pool.
Cast & Crew
The Doctor - Tom Baker
Sarah Jane Smith - Elisabeth Sladen
Baldwin - Tony McEwan
Braun - Terence Brook
De Haan - Graham Weston
Morelli - Michael Wisher
O'Hara - Haydn Wood
Ponti - Louis Mahoney
Reig - Melvyn Bedford
Salamar - Prentis Hancock
Sorenson - Frederick Jaeger
Vishinsky - Ewen Solon
Director - David Maloney