Written by Steve Gallagher, who had previously scripted the stories "Warriors' Gate" and "Terminus", this story was originally commissioned for season 21 but was ultimately rejected by the production team for being too expensive for the show's budget at that time, and Gallagher was not asked to write for the show again.
Nightmare Country contains examples of:
- Almost Out of Oxygen: Turlough and Volos' plan to force Konis out of hiding involves expanding the TARDIS' inner dimensions but leaving the amount of oxygen the same, so that Konis will have to expose himself or else run out of air to breathe.
- Amnesiac Hero: Inside the world of the reality engine, the Doctor has no idea who he is or what he's doing there, not that this stops him from saving the day and being generally clever. Everyone he meets in the virtual world also applies, but since they've been there much longer than him they've had time to build up more of an identity for themselves.
- Aw, Look! They Really Do Love Each Other:Tegan: Why are you being weird?Turlough: Nothing weird! I'm just happy to see you!Tegan: From you, that's beyond weird.
- Become a Real Boy: This is the Vodyani's ultimate goal, to transfer into the real world and stop being imaginary monsters in a virtual world.
- Bottle Episode: Technically, none of the characters in this story actually leave the TARDIS.
- Brain Uploading: In contrast to the people plugged directly into the reality engine who retain their physical forms and basic personalities but no memory, Volos is able to upload a complete engram of another person into the engine's world, memories fully intact, which is what he does with Tegan.
- Call-Back:
- The TARDIS' secondary console room is once again utilized. Since neither Tegan nor Turlough pass comment on its unusual design compared to the rest of the TARDIS, it's possible that this story is set after they first set foot in it.
- Konis hides away inside the TARDIS by creating a Zero Room for himself.
- Call-Forward: The Doctor might not have his memories, but he does know he doesn't enjoy being called "Professor".
- Deadpan Snarker: Tegan has very little patience for anyone in this story, and worrying about the Doctor on top of that only makes her snarking worse.Volos: And this must be... Miss Turlough.Tegan: I'm Tegan Jovanka. Miss Turlough's the ginger in the Upstairs Downstairs waistcoat.
- Dumb Muscle: Big Bob is heavy-set, very strong and can barely speak beyond the occasional grunt.
- Face Death with Dignity: Tegan's engram is quite sad that she has to die in the virtual universe, but she barely complains and gets on with the job. The Doctor makes sure to tell the real Tegan that her other self faced her death with "more grace than you could possibly imagine".
- Friendship Moment: The Doctor breaks the No Hugging, No Kissing rule to give Tegan's engram a big hug before he has to leave her behind in the virtual world. She is quite touched, if surprised. Later, when the Doctor creates his own engram to defeat the Vodyani for good, the two of them hold hands as the end comes.
- Gone Horribly Wrong: The Doctor volunteered to link himself up to the reality engine so he could help his friends the Guild of Reality Engineers build themselves a home world. The head engineer turns out to have a secret, sinister plot and it all becomes the usual desperate struggle for survival.
- Have You Tried Rebooting?: Turlough half-seriously suggests doing this with the reality engine to try and save everyone hooked into it, but naturally that would just kill them all.
- Improvised Weapon: Marzanna is able to rig up a makeshift flamethrower using rocket fuel.
- Inside a Computer System: The basic setup for the reality engine, though with a TARDIS involved it does become a bit more complicated.
- Mental Monster: As a side effect of everyone plugged into the reality engine having no memories, combined with the reality warping potential they have inside the engine, their subconscious fears and darker impulses physically manifest as the monsters of this story, the Vodyani.
- Mistaken for Romance: Tegan takes great offense to the Vodyani referring to her as the Doctor's "woman". Later, the amnesiac Doctor asks if there was some kind of romantic history between them and she hastily shuts that line of questioning down.
- Lovable Coward: Turlough cheated at the coin toss so that Tegan would be the one who had to create an engram in the virtual universe. She tells the Doctor she knew he'd done it, she just didn't think he could do the job as well as her.
- Nice Job Breaking It, Hero: Tegan sketches the TARDIS on a cave wall to try and jog the Doctor's memory. This clues the Vodyani into the fact that the TARDIS in the virtual world is the door back to the real one. The Doctor and Turlough agree that Tegan doesn't need to know this.
- Reality Warper: Limited to the world of the reality engine, but Konis has bigger plans for it. The Doctor first notices that something is amiss when he idly wishes for things and they suddenly turn up as if they'd always been there.
- The Reveal: It wasn't Konis' manipulations that created the nightmare world after all; he did early tests of the reality engine machinery on Volos and it latched onto his mind, deliberately recreating the war torn landscape of his childhood and thus bringing the Vodyani into being.
- Well-Intentioned Extremist: Konis was desperate to create a pocket universe to house his people, and deliberately deceived the Doctor and the engineers into joining up with the reality engine to harness the full power of their unconscious. He didn't believe anything would go wrong and had no way of knowing what would go wrong.
- You Are Better Than You Think You Are: Tegan does a bit of this (though, naturally, a fairly blunt version) in order to help Volos find his confidence and take charge of the engineering team.
- Your Mind Makes It Real: Anyone whose mind is connected to the reality engine can die in real life if anything happens to their virtual self. Naturally, the reverse is also true, as being hooked up to the machine is not without its risks.
