This season featured the first ever UNIT story, The Invasion, which showcased the return of Brigadier Lethbridge-Stewart. It also featured the first official appearance of Time Lords and the as yet unnamed Doctor's home planet (another member of Susan and the Doctor's race, the Monk, had appeared previously, but without much elaboration and without using the term "Time Lord"). It also marked the tenure of Patrick Troughton as the Second Doctor. It consisted of seven serials and forty-four episodes, including two epic-length storylines: the eight episodes of The Invasion and the ten-episode The War Games.

Season 6 Episode 1 - The Dominators (1)

The TARDIS arrives on the planet Dulkis where the Doctor, Zoe and Jamie decide to have a quiet holiday. Only to find the Evil Dominators and their robotic slaves, The Quarks have arrived on a radioactive island, where they plan to detonate a bomb in the planet's core, which will turn the entire planet as source of radioactive fuel for their invasion fleet. Air Date : 10th-Aug-1968  Read More

Season 6 Episode 2 - The Dominators (2)

The Doctor and Jamie are captured by the Dominators, who subject them to an intelligence test, while Zoe and Cully attempt to convince the Dulcian council of the threat. Air Date : 17th-Aug-1968  Read More

Season 6 Episode 3 - The Dominators (3)

Zoe and Cully are captured by the Dominators and put to work alongside the survey team while the Doctor and Jamie decide to return to the island to help. Air Date : 24th-Aug-1968  Read More

Season 6 Episode 4 - The Dominators (4)

The Doctor and Zoe are interrogated by Rago, who is planning to present his terms to the Dulcian council, while Jamie and Cully try to find a way to strike back against the Quarks. Air Date : 31st-Aug-1968  Read More

Season 6 Episode 5 - The Dominators (5)

Jamie and Cully manage to rescue the Doctor's party and together they try to find a way to stop the Dominators before they destroy the entire planet. Air Date : 7th-Sep-1968  Read More

Season 6 Episode 6 - The Mind Robber (1)

The TARDIS arrives in a white void, having made an emergency take-off to escape the volcanic eruption on Dulkis. The Doctor, Jamie and Zoe find themselves in the Land of Fiction, where characters from the imagination come to life, and The Master, the mysterious ruler, chooses the Doctor to take his place. Air Date : 14th-Sep-1968  Read More

Season 6 Episode 7 - The Mind Robber (2)

With the TARDIS destroyed, the Doctor, Jamie and Zoe find themselves in a strange forest patrolled by mysterious soldiers. Air Date : 21st-Sep-1968  Read More

Season 6 Episode 8 - The Mind Robber (3)

The Doctor realises that the travellers are trapped in a world where fiction is real and where creatures are a threat if people believe in them. Air Date : 28th-Sep-1968  Read More

Season 6 Episode 9 - The Mind Robber (4)

The Doctor, Jamie and Zoe reach the citadel at the centre of the land, where they finally encounter the Master of the Land of Fiction. Air Date : 5th-Oct-1968  Read More

Season 6 Episode 10 - The Mind Robber (5)

With Jamie and Zoe having been turned into fiction, the Doctor must find a way to save them without suffering the same fate or becoming part of the Master Brain. Air Date : 12th-Oct-1968  Read More

Season 6 Episode 11 - The Invasion (1)

The Doctor and the newly formed UNIT must stop a Cybermen Invasion and a Sinister Industrialist in league with them Air Date : 2nd-Nov-1968  Read More

Season 6 Episode 12 - The Invasion (2)

The Doctor and Jamie are taken prisoner by their mysterious observers and have a reunion with an old friend while Zoe and Isobel carry out their own investigation of IE. Air Date : 9th-Nov-1968  Read More

Season 6 Episode 13 - The Invasion (3)

The Doctor and Jamie return to the IE factory in search of Zoe and Isobel, where they meet with Professor Watkins and fall foul of Vaughn. Air Date : 16th-Nov-1968  Read More

Season 6 Episode 14 - The Invasion (4)

The Doctor and Jamie enlist the help of UNIT to rescue Zoe and Isobel before trying to find out what Vaughn is really up to. Air Date : 23rd-Nov-1968  Read More

Season 6 Episode 15 - The Invasion (5)

The Doctor and Jamie tell the Brigadier about the Cybermen but with Rutledge under Vaughn's control he is powerless to act. Air Date : 30th-Nov-1968  Read More

Season 6 Episode 16 - The Invasion (6)

Captain Turner manages to rescue Jamie and the others, while the Doctor begins working on a way to protect everyone from the Cybermen's hypno-sound signal. Air Date : 7th-Dec-1968  Read More

Season 6 Episode 17 - The Invasion (7)

With the entire world unconscious apart from the Doctor and his friends, the Cybermen are poised to invade and only Zoe, the Brigadier and a missile crew can stop them. Air Date : 14th-Dec-1968  Read More

Season 6 Episode 18 - The Invasion (8)

The Cybermen have launched their deadly megatron bomb which will destroy all life on Earth unless the Doctor can deactivate the homing signal. Air Date : 21st-Dec-1968  Read More

Season 6 Episode 19 - The Krotons (1)

When the TARDIS arrives on the planet of the Gonds, the Doctor, Jamie and Zoe discover a world ruled and enslaved by the Krotons. The brightest Gonds are always chosen to serve as companions of the Krotons and are never seen again... Air Date : 28th-Dec-1968  Read More

Season 6 Episode 20 - The Krotons (2)

Zoe is selected as a companion for the Krotons and the Doctor insists on joining her. Air Date : 4th-Jan-1969  Read More

Season 6 Episode 21 - The Krotons (3)

Jamie is held prisoner by the Krotons who intend to recapture the Doctor and Zoe for their mental energy. Air Date : 11th-Jan-1969  Read More

Season 6 Episode 22 - The Krotons (4)

Selris succeeds in drawing the Krotons out of the Dynatrope but Eelek agrees to hand the Doctor and Zoe over to them in return for their leaving the planet. Air Date : 18th-Jan-1969  Read More

Season 6 Episode 23 - The Seeds of Death (1)

21st century Earth is entirely dependent on the T-Mat transport system but the control centre on the moon has stopped functioning. Meanwhile, the Doctor, Jamie and Zoe meet the one man who can solve the crisis. Air Date : 25th-Jan-1969  Read More

Season 6 Episode 24 - The Seeds of Death (2)

Eldred agrees to supply a rocket for travel to the moon and the Doctor, Jamie and Zoe volunteer to crew it. Air Date : 1st-Feb-1969  Read More

Season 6 Episode 25 - The Seeds of Death (3)

The Doctor, Jamie and Zoe make it to the moon and join forces with Phipps but the Ice Warriors have gained control of T-mat. Air Date : 8th-Feb-1969  Read More

Season 6 Episode 26 - The Seeds of Death (4)

The Ice Warriors' seed pods beginning materialising all over the globe while Slaar decides to kill the Doctor by T-matting him into space. Air Date : 15th-Feb-1969  Read More

Season 6 Episode 27 - The Seeds of Death (5)

The Doctor and his allies manage to return to Earth via T-mat only to find the Ice Warrior has attacked the weather control station. Air Date : 22nd-Feb-1969  Read More

Season 6 Episode 28 - The Seeds of Death (6)

The Doctor manages to create a rain storm to destroy the Martian fungus before trying to find a way to stop the Ice Warriors' invasion fleet. Air Date : 1st-Mar-1969  Read More

Season 6 Episode 29 - The Space Pirates (1)

Space beacons are being destroyed by pirates, who are salvaging the argonite metal. When the Doctor, Jamie and Zoe arrive on one of the beacons, they are mistaken for pirates. Air Date : 8th-Mar-1969  Read More

Season 6 Episode 30 - The Space Pirates (2)

With the Doctor, Jamie and Zoe trapped on a beacon segment, Hermack becomes suspicious of the unruly prospector Milo Clancey. Air Date : 15th-Mar-1969  Read More

Season 6 Episode 31 - The Space Pirates (3)

The Doctor, Jamie and Zoe flee from the Space Corps with Clancey, who decides to seek refuge on Ta. Air Date : 22nd-Mar-1969  Read More