This week, Doctor Who meets a man who has turned into a big hairy slime mutant.
He looks frankly ridiculous and is, quite rightly, hoping no-one has seen him.
Doctor Who reacts to this by getting sucked into a parallel universe. It makes his entire face slide off.
This ruins his hair, which is why he's pulling that sad face.
In the parallel universe, all Doctor Who's friends are evil.
That's evil Sergeant Benton, next to him. You can tell he's evil, because of the evil face he's pulling. Normal Sergeant Benton would never pull such a face, and Doctor Who knows it.
Even the Brigadier has gone evil in this universe. Though with him it just means he shoots a slightly wider range of people than usual.
I like the picture in the background. I think it's meant to be the leader of the whole country.
He looks furious. But I suppose the administration of a country where everyone is evil must be quite demanding. Loads of your council tax bill would have to go on policing, for example, and I bet no-one pays their TV licence.
Back in the normal universe, not-evil Brigadier and Liz are watching an argument between these two snappy dressers.
The guy on the left is saying "Don't drill into the earth - it will make everyone into slime monsters, and then the world will blow up."
The guy on the right is saying, "That sounds awesome. I'm definitely doing it."
Because they do carry on drilling into the earth, loads more slime mutants turn up. They look amazing.
The leader here is asking if anyone wants to see the dance routine they have been practicing.
The lady is thinking it would be rude to say no, especially as they have arranged dry ice.
The dance routine does not go well and many, many people die.
The slime mutants are plunged into a depression which lasts for the rest of the story.
The alternative universe explodes, but not before Doctor Who tells them all that they are jerks and that he definitely wouldn't ever come back, even if the whole place wasn't about to blow up.
Evil Brigadier responds by pulling possibly the stupidest expression anyone has ever pulled. He talks tough, but he's not really ready for such harsh criticism and his personality has collapsed in direct response.
Evil Liz is just smouldering at the camera. She dies as well, and then - in the normal universe - Real Liz leaves the show forever. A shame, as she was lots of evil, sexy fun.
That's all for Season 7. It's a strange one, full of serious drama, subtle characterisation and also dinosaurs and werewolves. Good old Doctor Who.