The Doctor - Tom Baker
Sarah Jane Smith - Elisabeth Sladen
Harry Sullivan - Ian Marter
Lethbridge-Stewart - Nicholas Courtney
RSM Benton - John Levene
Duke of Forgill/Broton - John Woodnutt
Sister Lamont - Lillias Walker
The Caber - Robert Russell
Angus - Angus Lennie
Huckle - Tony Sibbald
Munro - Hugh Martin
Radio Operator - Bruce Wightman
Corporal - Bernard G. High
Soldier - Peter Symonds
Zygon - Keith Ashley
Zygon - Ronald Gough
Manager - Rosemary Webb
Costumes - James Acheson
Designer - Nigel Curzon
Film Cameraman - Peter Hall
Film Editor - Ian McKendrick
Incidental Music - Geoffrey Burgon
Make-Up - Sylvia James
Producer - Philip Hinchcliffe
Production Assistant - Edwina Craze
Production Unit Manager - George Gallaccio
Script Editor - Robert Holmes
Special Sounds - Dick Mills
Studio Lighting - John Dixon
Studio Sound - Michael McCarthy
Theme Arrangement - Delia Derbyshire
Title Music - Ron Grainer
Visual Effects Designer - John Horton
When The Doctor,
Sarah Jane and Harry arrive in Scotland, having received an
urgent request for assistance from The Brigadier, they discover
that the mysterious force which has destroyed three oil rigs has
left giant teeth marks on the wreckage.
The mystery deepens, leading them to the shores of Loch Ness
where they find that the legendary monster really does exist -
and is the murderous tool of the Zygons, aliens intent on
overpowering the planet.
The Doctor, his companions and UNIT must find a way to defeat
the deadly Loch Ness Monster and its controllers, but the Zygons
have the terrifying power to change shape. The Doctor's life has
never been in more danger, as the line between allies and
enemies is tested to the very limit...
On an oil rig off the coast of Scotland, a strange, high-pitched
beeping sound echoes through the structure. It begins to break
apart, collapsing into the North Sea.
The Fourth Doctor, Harry and Sarah hitch a ride with a motorist
to the town where the Brigadier and UNIT have set themselves up
in an inn. The Brigadier is talking to Huckle, an official of
Hibernian Oil, who owned the rig. Huckle complains that three
rigs have been destroyed in the last month, two of them
belonging to Hibernian. The Brigadier assures Huckle that UNIT
is also concerned, especially about the loss of life.
The Doctor, Harry and Sarah arrive at the inn. It turns out that
their ride is the Duke of Forgill, a local landowner. The Duke
is angry about Huckle's men trespassing on his land. Huckle
assures him that he has warned his employees about this, and any
who are caught will be dismissed without question. However, the
Duke warns that any of Huckle's men caught on his land will be
shot. He also wants to know what UNIT are doing here, but the
Brigadier says that it is a sensitive matter. Though not
pleased, the Duke leaves.
On the shoreline, a survivor of the destroyed rig washes up,
barely alive. The Brigadier brings the Doctor, Harry and Sarah
to Hibernian Oil, where Huckle briefs them on the injuries of
the rigs' crew. Harry decides to examine the injuries at the
sickbay, while Sarah goes to talk to some of the locals. Huckle
cannot understand it: the rigs were designed to be unsinkable
and the seas were calm and empty before the incidents. The
Doctor darkly notes that the sea is never empty.
Back at the inn, Sarah talks to Angus, the landlord. She admires
a stuffed stag's head above the fireplace, a gift from the Duke
just this past week. Angus observes that the Duke has not been
himself since the oil companies came. His servants have gone to
work for them, leaving Forgill Castle cold and empty. He tells
Sarah about Tulloch Moor and people disappearing over the
centuries when the mist comes down. Sarah is sceptical — evil
spirits do not destroy oil rigs. All this while, something alien
watches Angus and her on a monitor screen.
The Duke's man, the Caber, sees the rig survivor, Munro, stagger
from the surf. Harry is driving by and and goes to Munro as he
collapses. Before Munro can tell Harry about what smashed the
rig, the Caber fires a rifle, killing Munro and creasing Harry's
forehead with a second shot. Harry falls, unconscious. Back at
the inn, the Doctor is working on a radio probe to check for
localised jamming when a call comes in informing them about
Alien hands manipulate strange, organic controls. A high-pitched
beeping summons a creature from the depths. It heads towards the
Ben Nevis rig. The rig's communications with Huckle are jammed.
The Doctor and Sarah visit Harry, who is sedated and being
tended by Sister Lamont, the nurse. The Brigadier arrives to
tell him of the Ben Nevis rig's destruction. Sarah stays with
Harry while the Doctor goes with the Brigadier. Outside, the
Doctor spots wreckage from the rig with odd holes in it. He asks
Sergeant Benton for plaster of Paris and makes a mould of the
holes, revealing that something with very large teeth bit the
rig. The watching aliens decide that the Doctor knows too much
and must be destroyed.
Harry awakens. Sarah goes to tell the Doctor while Sister Lamont
tells Harry he will be very well looked after. A high-pitched
beeping echoes through the room and Harry looks up in fear. As
Sarah calls the Doctor, a suction-tipped hand clamps down on her
shoulder. She turns as she is grabbed by a large, orange biped
The Doctor hears Sarah's cries over the telephone and rushes to
the sickbay. Sister Lamont tells them that she found Sarah gone
and Harry's bed empty. The Doctor snoops around and finds Sarah
unconscious in a decompression chamber. As Sarah comes round and
starts telling the Doctor about what happened, a Zygon locks
them in and starts to remove the air from the chamber. To escape
death, the Doctor hypnotises Sarah into not needing to breathe
and then puts himself in a similar trance.
Harry is brought to the Zygon ship deep underwater, where he
meets their warlord, Broton. Centuries ago, their spaceship was
damaged and they landed on Earth. They were waiting for rescue
when they heard that their world had been destroyed in a stellar
explosion. No, they intend to claim Earth for their own, using
the sea monster under their command, an armoured cyborg of great
power. Broton explains that the Zygons depend on the lactic
fluid of the Skarasen. Harry realises that if the monster is
destroyed, the Zygons will die. Broton declares that no human
weapon can affect the Skarasen.
The Brigadier is briefing one of his officers at the inn when
gas floods the room, knocking them all out. Meanwhile, Benton
has found the Doctor and Sarah. He opens the pressure door. The
Doctor exhales, awakens and carefully revives Sarah. He tells
Benton the trance was a trick he picked up from a Tibetan monk.
The Doctor, Sarah and Benton find the entire village has been
drugged by some kind of nerve gas, but they soon revive. The
Doctor deduces that this was done so that something could get
around unseen. The Zygons watch Huckle give the Doctor a device
he found in the wreckage: the signal device that summons the
Skarasen. Broton says it must be recovered. Harry is taken to
another room in the ship, where he sees other humans hooked up
to booths, providing the Zygons with "body prints" that they use
to assume human form.
The Doctor hypothesises that the signal device sends out a
primeval mating call to attract the beast. The savaged body of a
UNIT soldier is found on the Moor and the Doctor and the
Brigadier go to see it, leaving Sarah behind in case Harry turns
up. He does, but it is his Zygon duplicate Madra. He takes the
signal device, saying that the Doctor asked him to collect it.
Sarah notices his curious behaviour and questions him, but he
pushes her aside and runs away. Sarah and some soldiers pursue
Sarah discovers 'Harry' hiding in an upper level of a barn and
he attacks her with a pitchfork. She steps aside at the last
moment and he falls, impaling himself on his weapon and turning
back into a Zygon. The signal broken, Broton realises Madra is
dead, and remotely disperses the corpse. Harry, however, is
freed from his body print booth.
Sarah wonders how the aliens knew they had the signal device.
The Brigadier orders the inn searched for bugs. Broton in turn
orders the Skarasen unleashed, even if it reveals their
presence. The signal device begins to beep. The Doctor grabs it
to lure the creature away while the Brigadier tries to get a fix
on the activating signal.
The Skarasen catches up to the Doctor on the Moor and he finds
that he cannot get rid of the semi-organic signal device which
has fastened itself to his palm. The Brigadier traces the
incoming signal to Loch Ness. As the Doctor stumbles, Broton
orders the Skarasen to destroy him.
Harry rushes into the Zygon control room and randomly hits
controls, making the device fall off the Doctor's palm and
allowing him to roll out of the Skarasen's way. Since the device
is dead, Broton assumes that the Doctor is too and recalls the
Skarasen. The Doctor retrieves the device and makes his way back
across the moor as the Skarasen glides away. In the ship, Harry
is dragged away by the other Zygons.
The Doctor is met halfway by the Brigadier and Sarah, who tell
him that the signal came from Loch Ness. The Doctor decides to
visit Forgill Castle, right next to the loch. They get a frosty
reception from the Duke, who does not believe them about the
monster, aliens and their intention to drop depth charges in
At the inn, Angus discovers the Zygon surveillance link in the
stuffed deer head that was the Duke's gift. As he tries to pry
it loose, Sister Lamont enters the inn. The sister turns into a
Zygon and kills him, removing the link after. Angus' dying cries
are heard by Benton and some UNIT soldiers, who discover the
body and pursue the killer. The UNIT troops sweep through the
nearby forest and fire on the Zygon.
The Brigadier is told a Zygon is being cornered. The Doctor and
he leave Sarah at the castle to research the monster. In the
woods, the wounded Zygon disguises itself again as Sister Lamont
and fools a UNIT soldier long enough to knock him out and steal
his jeep. At the inn, the Doctor notices the missing eye in the
deer head and realises that the Duke may be a Zygon facsimile.
At the castle, Sarah examines the upper bookshelves. She
triggers a hidden switch and a section of the bookcases slides
open, revealing a passage. She takes a torchlight and goes in,
following a long dark tunnel that leads to the Zygon ship. 'The
Duke' (in reality Broton) finds the open bookcase. He and 'the
Caber' take the wounded 'Sister Lamont' (the Zygon Odda) into
the ship; the crew must be alerted and the intruder found and
Sarah finds the cell where Harry is held. She frees him and they
sneak back to the castle, just in time to meet the Brigadier and
the Doctor. Sarah tells the Brigadier about the Zygon ship. The
Doctor enters the tunnel, but does not get far; a scream is
heard. The Zygons emerge in their true forms. Broton tells the
humans that they are leaving with the Doctor as their prisoner.
He warns them the oil rigs were only a test; the "big event" is
yet to come. Broton retreats, sealing the entrance to the
The Brigadier orders the loch depth-charged to bring the Zygon
ship to the surface. The Zygon ship does rise, but keeps on
rising into the sky, flying away.
Broton orders a jamming signal transmitted to block the humans'
radar systems. The Brigadier prepares to move his troops out,
but Sarah and Harry suggest they search Forgill Castle before
they leave for clues to the Zygons' plans. Sarah finds some
papers that indicate the Duke is the President of the Scottish
Energy Commission, but Harry dismisses the information as
useless. They return with the Brigadier to London.
The Zygon ship lands in a disused quarry. UNIT cannot track it.
Radar stations are knocked out all over the country. However,
there are reports of a large underwater object heading south at
high speed. Broton enters the Doctor's cell and, taking the
Duke's form again, tells him that Phase I of the conquest of
Earth is complete. A great Zygon refugee ship is on its way, but
will take some centuries to arrive. In the meantime, Earth's
environment must be restructured with human labour and Zygon
technology to turn it into a new homeworld.
Left alone, the Doctor rigs some of the organic technology in
his cell, electrocuting himself but sending a transmission to
help UNIT track the ship to the quarry. By the time Broton and
his men open the Doctor's cell door, the Doctor is apparently
dead. However, when Broton leaves, the Doctor comes to. He makes
his way to the body print chamber and frees the real Duke,
Sister Lamont and the Caber.
Broton leaves the ship to plant a signal device on his target,
which the Skarasen will then destroy, proving the power the
Zygons hold. When Phase II is complete, he will broadcast his
demands to the world. Inside the ship, the Doctor uses his sonic
screwdriver to set off the fire sensor, triggering an alarm.
When the Zygons go to investigate, the Doctor ushers the humans
out of the ship, jamming the hatches and activating the ship's
The Brigadier has arrived and the escapees reach UNIT's
position. The Doctor shouts for everyone to get down just before
the Zygon ship explodes. However, Broton is still free and has
control of the Skarasen. The target is in London and must be
close to the River Thames. The Brigadier says the Prime Minister
will be at a conference at Stanbridge House, near the river. The
Duke adds it is the first International Energy Conference, with
delegates from all over the world. As the Duke is the President
of the Scottish Energy Commission, Broton will have a pass into
the meeting. They leave for London.
'The Duke' places the signal device in the basement of
Stanbridge House. The Skarasen has been sighted mere minutes
away. The Doctor finds Broton, back in his true form, who swears
he will make sure the Doctor is dead this time and attacks him.
Sarah calls for the Brigadier, who arrives to shoot Broton dead.
The Doctor finds the signal device in his pocket and feeds it to
the Skarasen as it rises out of the Thames. After it consumes
the device, the beast sinks back into the river and heads back
to Loch Ness, the only home it has ever known.
Returning to Scotland, the Brigadier tells the Duke that the
incident will be kept quiet, even the appearance of a fifty foot
monster in the Thames. The Doctor leads them into the woods to
the TARDIS and offers all of them a lift. The Brigadier and
Harry decline. Sarah agrees on the condition they go straight
back to London. The Doctor promises and the TARDIS takes off.
The Duke tells the Brigadier that, as a Scotsman, he should have
gotten a refund for Sarah and the Doctor's return train tickets.
[Source: TARDIS Wikia]
The Secret of the Loch
Secret of Loch Ness
The Loch Ness Monster and The Zygons
Things to look out for:
The Doctor is summoned back to Earth
with the space-time telegraph he left with the Brigadier.
The Doctor drives a UNIT Land Rover out to the moor.
■ All 4 Episodes exist in
the BBC Archives.
■ Coming Soon
To be released June 2013.
Terror Of The Zygons
Manufactured by: Encore Entertainment (cat #EE1203)
Format: PAL UK -
Terror Of The Zygons
Manufactured by: BBC Music (cat #WMSF
23rd May 2000
Released as a 2-CD set together
with The Seeds Of Doom. The
Terror Of The Zygons portion of the set
contains 18 tracks.