The Doctor, trying to return Tegan to Heathrow Airport, manages to get the TARDIS to the correct time and date – but in the wrong place, landing aboard a vast spaceship which is slowly making its way toward Earth. The Doctor and his friends eventually meet Monarch, ruler of the alien Urbankans, who are preparing to visit Earth on what Monarch claims is a mission of peace. But it seems that the Urbankans have already paid Earth a visit – representatives of various periods and cultures in the planet’s past. But none of it is real – the “abductees” aren’t really human, and Monarch’s mission is one of conquest, not peace.
written by Terence Dudley
directed by John Black
music by Roger LimbGuest Cast: Stratford Johns (Monarch), Philip Locke (Bigon), Paul Shelley (Persuasion), Annie Lambert (Enlightenment), Burt Kwouk (Lin Futu), Illario Bisi Pedro (Kurkutji), Nadia Hammam (Villagra)
Broadcast from January 18 through 26, 1982
LogBook entry & review by Earl Green
Review: An interesting story is let down by some of the Davison era’s worst character writing. Where Four To Doomsday sinks the lowest is in its portrayal of the Doctor’s three companions. Though Adric has some distinct personality problems, and Doctors and companions had bickered and would continue to argue before and after this story, this was really the low point in terms of writing Tegan, Nyssa and Adric. In the second half of the story, Tegan and Nyssa actually fight each other physically, and a hysterical Tegan even hijacks the TARDIS, leaving the Doctor, Nyssa and Adric stranded on Monarch’s ship in a hostile situation. While she does have a good reason to try to move the TARDIS – she’s trying to reach Earth to warn them of the impending invasion – her endangerment of the only people who could stop that very invasion is almost inexcusable. And, between this story and State Of Decay, Adric’s vulnerability to the lure of power makes him a liability as well. All of these things don’t exactly make Tegan and Adric sympathetic characters that the audience 
would enjoy watching on a regular basis, not to mention the average viewer wondering why the Doctor would allow them to keep traveling with him in the first place.
There’s also the time-filling argument between the three companions in the TARDIS in part one as the Doctor explores outside. For no readily apparent reason, Adric bleats a number of sexist insults, again taking him down several notches in the audience empathy department.
Still, it’s not all bad. As science fiction concepts go, Four To Doomsday‘s basic premise is sound, and there’s a very interesting zero-G sequence where the Doctor is trying to reach the TARDIS – it may not be Apollo 13, but for the BBC, it’s very good indeed. Though it may seem like a strange thing to focus on, this story’s sets were very interesting too, very functional-looking and chunky, with those cool doors that would light up when they opened.