Apparently, this writers of this serial intended it to be like an Agatha Christie novel.
I can think of worse inspirations for a silly, low budget sci-fi show.
We begin the serial on a large sand crawler of some kind on an alien world because we have to begin somewhere. Inside the thing are a lot of silly-looking robots and a handful of silly-looking humans. It’s a mining ship where most of the work is robotic. That means the handful of silly-looking humans can do as little as possible.
Looks like a sweet life. Robots, we’re told, can’t hurt anybody because that would violate a few thousand subroutines. Or maybe just the Laws of Robotics. Given the title of the serial, you know robots will hurt someone at some point.
And that point happens when a robot murders a scientist on the crawler.
However, no one thinks the robots could do such a thing, so everyone gathers in the lounge to yell and cast side-eye. Sounds like my last department meeting. Actually, that would be more fun than my last department meeting. My department needs more side-eye.
Anyway, that would be about when the TARDIS materializes inside the giant thing. The Doctor and Leela come out with the Doctor telling her to leave the ray gun behind. See, when you come unarmed, people are more likely to be friendly except when they aren’t.
She still brings a knife.
That’s probably a good thing. Since there are two strangers on the crawler, the crawler’s commander thinks they must be the killers. As such, they can just send the robots to bring them in or something. That even works for a period, but you can’t keep the Doctor in a prison cell if he doesn’t want to stay there. The Doctor believes robots are only helpful. Clearly he has missed a few of the more violent ones in his journeys.
So, after being in a cell for all of five minutes, the Doctor and Leela go out and look around. The two separate when the Doctor isn’t looking. Leela finds the first corpse. The Doctor finds the TARDIS, something the crawler brought inside because it didn’t belong where it was. Since this is the reactor room, the Doctor finds a door with a lot of sand in it. Also, there’s another corpse in there. That can’t be good.
It really isn’t good when the door behind him closes. It’s even worse when the sand starts to come down to bury the Doctor alive.
Maybe next time he should keep a better eye on his companions. Always use the buddy system, people.