The Guardians of Time are the most powerful beings in the cosmos. The Black Guardian and the White Guardian are polar opposites and they counterbalance the darkness and the light in the universe. Both of them sought the Key to Time, which restores balance to the fictional universe of Doctor Who. The White Guardian enlisted the help of both the Fourth Doctor and Romana to find the six segments to the Key to Time (The Ribos Operation). After finding the sixth and final segment on the planet Zeos, Romana and the Doctor were contacted by the Black Guardian, in disguise as the White Guardian (The Armageddon Factor). The Black Guardian tried to trick the Doctor into handing over the Key to Time, but the Doctor saw through this and fixed a randomiser to the TARDIS console, to prevent the Black Guardian from following him and Romana. Years later, the Black Guardian (Valentine Dyall) enlisted the help of a man called Vislor Turlough to assassinate the Fifth Doctor (Mawdryn Undead). Turlough travelled with Nyssa and Tegan in the TARDIS but could not bring himself to kill his new friend, the Doctor (Terminus). In a final confrontation in Enlightenment, Turlough rejected the bargain he made with the Black Guardian and the Black Guardian was banished, allowing Turlough to continue travelling with the Doctor and Tegan.

Mawdryn Undead

★★★★☆

TX: 01-09/02/1983

Written by Peter Grimwade    Directed by Peter Moffatt

A public school boy called Vislor Turlough is trapped on Earth and desperate to get back to his home planet of Trion. After being involved in a car crash, a being called the Black Guardian strikes a deal with Turlough: he will allow him to return home in exchange for assassinating a person called the Doctor. The Fifth Doctor, Tegan and Nyssa are caught in a warp eclipse cutout, where they discover a spaceship that is linked to Earth by two transmat capsules. The Doctor transmats down to Earth, to the public school that Turlough attends in the year 1977. The Doctor meets Brigadier Lethbridge-Stewart who has now retired from U.N.I.T and works as a maths teacher at the school. Tegan and Nyssa follow them in the TARDIS, but it arrives at the school in 1983, during the Queen’s Silver Jubilee Celebrations, where Tegan meets an older Brigadier. Nyssa discovers the capsule containing an alien fugitive called Mawdryn, who disguises himself as a regenerated Doctor. The Brigadier, Nyssa and Tegan are mistrustful of Mawdryn, but dare not take the risk. Mawdryn instructs them to take him back to his ship full of fellow mutants who tried to turn themselves into Time Lords, but the experiment went hideously wrong and now they live in agony and crave death via euthanasia. Mawdryn begs the Doctor to surrender his remaining regenerations to help them die, although this will mean that the Doctor will cease to be a Time Lord. Meanwhile, two Brigadiers (one from 1977 and the other from 1983) have accidentally wandered onto Mawdryn’s ship, and the Black Guardian instructs Turlough to keep them apart. However Turlough fails to do this and so the two Brigadiers meet in the laboratory and when they touch, this shortens out the time differential, creating the energy needed to end the lives of Mawdryn and his fellow mutants. The Doctor, Nyssa, Tegan and Turlough return the two Brigadiers to their proper times and places. Nyssa and Tegan do not trust Turlough, but the Doctor invites him aboard the TARDIS anyway.

Terminus

★★☆☆☆

TX: 15/02/1983 – 23/02/1983

Written by Stephen Gallagher    Directed by Mary Ridge

The Fifth Doctor, Tegan, Turlough and Nyssa discover a dimensional time crack in the TARDIS that leads to Terminus, a hospital at the centre of the known universe. Terminus is a facility where the sufferers of Lazar’s disease, an ailment similar to leprosy, are cured. However, the methods for curing the Lazars are far from ethical. Terminus is staffed by the Vanir who are enslaved by the company that runs Terminus because they are dependent on the company’s supply of Hydromel. Two intruders have boarded Terminus to find out what is going on there. The Doctor discovers that Terminus is at the exact centre of the known universe. Tegan and Turlough hide from the contagious Lazars. Nyssa is taken by the dog-like Garm to be cured along with the other Lazars. The Vanir and the Garm are both names taken from Norse mythology. Incidentally, my late grandfather was Norwegian (hence my Norwegian surname Olsen). Nyssa discovers that the Lazars are being cured in a chamber within Terminus. The Doctor reveals that Terminus jettisoned its fuel back in time aeons ago, which caused the Big Bang and created the universe in the first place. A second fuel jettison would undoubtedly destroy the universe. The Garm comes to the Doctor’s aid and uses its strength to hold the switch in place, preventing the fuel jettison. Having saved Terminus, Nyssa decides to stay behind and help. She offers to make an independent supply of Hydromel for the Vanir, so that they are free from the Company. Tegan and the Doctor reluctantly say goodbye to Nyssa, concerned for her safety. The pair leave with Turlough in the TARDIS. The Black Guardian is annoyed with Turlough for continually failing to honour their agreement for him to kill the Doctor, so he gives him one final chance. Despite a promising script from Stephen Gallagher, Terminus‘s production was negatively affected by the replacement of Mary Ridge as director.

Enlightenment

★★★★★

TX: 01/03/1983 – 09/03/1983

Written by Barbara Clegg   Directed by Fiona Cumming

The TARDIS materialises on a galleon floating through space as part of a race to Enlightenment. The Eternals use gigantic bow ships staffed by ephemerals, which are slaves from other species. Turlough is commanded by the Black Guardian to kill the Doctor, but he refuses and jumps off the side of the ship. Turlough is put on furlough by the Black Guardian. Turlough is captured by Captain Wrack (Lynda Baron) and brought aboard her ship. Tegan and the Doctor are invited over for a formal party, but Wrack places a bomb in Tegan’s tiara whilst she is under hypnosis. I partied and went clubbing all the way through university and especially when I was in student halls. The Doctor confronts Captain Striker (played by Keith Baron, but the part was originally offered to Peter Sallis) who claims that ephemerals are completely dispensable and that the race for Enlightenment is more important than their lives. The ships eventually arrive at their destination and Turlough is presented with a choice by the Black and White Guardians: kill the Doctor and take Enlightenment or go back on his agreement with the Black Guardian. Turlough chooses to spare the Doctor and give up Enlightenment. The Black Guardian is banished. The Doctor says that Enlightenment was not the diamond, it was the choice. Turlough joins the TARDIS as a proper crew member and he is no longer an assassin for the Black Guardian.