The Doctor, Jo Grant, and Brigadier Lethbridge-Stewart, head of U.N.I.T., continue investigating extraterrestrial threats, with help from Sergeant Benton and Captain Mike Yates.
During their adventures, the Doctor and Jo face the Daleks as they disrupt a peace conference and visit a distant planet Peladon for the first time, which hopes to join the Galactic Federation. They also confront the Master once again as he attempts to revive a colony of Sea Devils on Earth.






At a crucial Peace Conference, Sir Reginald Styles is almost assassinated.
Jo is transported to the 22nd Century where she unwittingly gives vital information to the Daleks.
The Doctor arrives in a bleak future where Earth is ruled by the Daleks and mankind is enslaved.
The Daleks travel back in time to the 20th Century to ensure that the peace conference fails.
The planet Peladon is hoping to join the Galactic Federation. But King Peladon's Chancellor has been murdered.
The work of the committee is hampered by sabotage, fear and suspicion.
The Doctor is sentenced to a fight to the death in the pit with the King's champion, Grun.
Hepesh, supported by the delegate from Arcturus, is revealed to be behind the attacks.
The Doctor and Jo visit the Master who is held prisoner on an island.
The Doctor is eager to make peace between the Sea Devils and the humans.
Jo attempts to rescue the Doctor who is being held prisoner by the Master and Trenchard.
The Doctor attempts to persuade Captain Hart of the danger that the Master represents.
The Doctor is captured by the Sea Devils and taken to their undersea base.
The Sea Devils come to the surface and attack the Naval base.
The Doctor is sent to a skybase orbiting the planet of Solos in the 30th century.
Ky flees to the planet's poisonous surface taking Jo with him while the Marshal, holds the Doctor captive.
The Doctor searches for Jo in the caves of Solos. In the shadows the mutants prepare to attack.
The Doctor and Sondergaard make an amazing discovery in the caves while Jo falls into the Marshal's trap.
The Marshal's plans for Solos go disastrously wrong. The Doctor needs to save the planet.
The Marshal is on trial, with the Doctor as chief witness. Jo and the Doctor's friends are the Marshal's prisoners.
The Master is using a device called TOMTIT to summon a creature from beyond time.
After a disastrous attempt to summon Kronos, the Master prepares to use TOMTIT once again.
The Master uses TOMTIT to summon threats from the past to attack UNIT.
The Master heads to Atlantis but he and The Doctor confront each other in the time vortex.
In Atlantis the crystal of Kronos is protected by a guardian who is half man, half beast.
With the crystal of Kronos in his possession, the Master releases the Chronovore.
Third Doctor
Jon Pertwee
Alistair Gordon Lethbridge-Stewart
Nicholas Courtney
Jo Grant
Katy Manning
Controller
Aubrey Woods
Mike Yates
Richard Franklin
John Benton
John Levene
Anat
Anna Barry
Shura
Jimmy Winston
Boaz
Scott Fredericks
Sir Reginald Styles
Wilfred Carter
Miss Paget
Jean McFarlane
Girl Technician
Deborah Brayshaw
UNIT Radio Operator
Gypsie Kemp
Guerilla
Tim Condren
Monia
Valentine Palmer
Manager
Peter Hill
Senior Guard
Andrew Carr
Guard at Work Centre
George Raistrick
Television Reporter
Alex MacIntosh
Third Doctor
Jon Pertwee
Jo Grant
Katy Manning
King Peladon
David Troughton
Hepesh
Geoffrey Toone
Torbis
Henry Gilbert
Izlyr
Alan Bennion
Ssorg
Sonny Caldinez
Alpha Centauri
Arcturus
Murphy Grumbar
Arcturus
Terry Bale (Voice)
Grun
Gordon St Clair
Aggedor
Nick Hobbs
Guard Captain
George Giles
Amazonia
Wendy Danvers
Third Doctor
Jon Pertwee
The Master
Roger Delgado
Jo Grant
Katy Manning
Captain Hart
Edwin Richfield
Trenchard
Clive Morton
Robbins
Royston Tickner
Radio Operator
Neil Seiler
Clark
Declan Mulholland
Hickman
Hugh Futcher
3rd Officer Jane Blythe
June Murphy
Ldg. Telegraphist Bowman
Alec Wallis
Castle Guard Wilson
Brian Justice
Castle Guard Barclay
Terry Walsh
Sea Devil
Pat Gorman
C.P.O. Smedley
Eric Mason
Castle Guard Drew
Stanley McGeagh
Commander Ridgeway
Donald Sumpter
Lt. Commander Mitchell
David Griffin
Ldg. Seaman Lovell
Christopher Wray
C.P.O. Summers
Colin Bell
Lt. Commander Watts
Brian Vaughan
A/B Girton
Rex Rowland
Walker
Martin Boddey
Rear Admiral
Norman Atkyns
Chief Sea Devil
Peter Forbes-Robertson
C.P.O. Myers
John Caesar
Third Doctor
Jon Pertwee
Jo Grant
Katy Manning
Marshal
Paul Whitsun-Jones
Varan
James Mellor
Ky
Garrick Hagon
Administrator
Geoffrey Palmer
Stubbs
Christopher Coll
Cotton
Rick James
Varan's Son
Jonathan Sherwood
Jaeger
George Pravda
Sondergaard
John Hollis
Old Man
Sidney Johnson
Warrior Guard
David Arlen
Third Doctor
Jon Pertwee
Skybase Guard
Martin Taylor
Mutt
John Scott Martin
Investigator
Peter Howell
Third Doctor
Jon Pertwee
The Master
Roger Delgado
Jo Grant
Katy Manning
Alistair Gordon Lethbridge-Stewart
Nicholas Courtney
Mike Yates
Richard Franklin
John Benton
John Levene
Dr. Ruth Ingram
Wanda Moore
Stuart Hyde
Ian Collier
Dr. Percival
John Wyse
Dr. Cook
Neville Barber
Proctor
Barry Ashton
Window Cleaner
Terry Walsh
Krasis
Donald Eccles
Hippias
Aidan Murphy
Neophite
Keith Dalton
The Master
Roger Delgado
Unit Sergeant
Simon Legree
Kronos
Marc Boyle
Dalios
George Cormack
Knight
Gregory Powell
Roundhead Officer
Dave Carter
Farmworker
George Lee
Galleia
Ingrid Pitt
Crito
Derek Murcott
Lakis
Susan Penhaligon
Miseus
Michael Walker
Minotaur
Dave Prowse
Guard
Melville Jones
Face of Kronos
Ingrid Bower