MR 025: Colditz

You shot my friend! Oh hey it's David Tennant. You shot my friend! First appearance of Klein, nice, I remember her. YOU SHOT MY FRIEND!

Well this one was quite good. There's some very interesting ideas about time travel here which I'll go into in a second. The Nazi stuff makes for some very interesting backdrop for the arrival of a mysterious woman named Klein who may not be what she claims to be. Also, a pre-Tenth Doctor David Tennant playing a creepy/sleezy Nazi guard! He orders Ace to take her clothes off and implies sexual favors from her. Tennant is always good at playing the villain and he's good at it here too.

The TARDIS makes a landing right outside of Colditz Castle, a famous Nazi prison. The Doctor and Ace quickly get captured. Ace tries to escape while the Doctor gets taken by Klein. Klein gives the Doctor's TARDIS to the prison's commander and then takes off. But it turns out her method of transport is gone. This is where it gets interesting.

Klein, it turns out, is from a timeline where the Nazis won. She's from the 60s in the UK in that timeline and is working on a government project studying the TARDIS. In this original timeline, Ace gets shot trying to escape Colditz and the Doctor leaves in his TARDIS, only to come back a decade later and get captured and shot when the Nazis won. They were able to use the technology in Ace's CD walkman to win the war, using lasers.

However, it turns out Klein has been tricked by a future version of the Doctor into coming back in time and changing history. She works with a future Doctor who convinces her to go back and capture the Doctor. She tampers with her own timeline and her intervention is what prevents Ace from being shot and prevents the TARDIS from falling into Nazi hands and prevents them from winning. Hence the trick. The future Doctor has been clever, seeing how her interference would wipe out her timeline.
The discussion between the Doctor and Klein is very interesting as well. The Doctor argues for his usual "changing history is bad in and of itself" bullshit. And Klein rightfully calls him out on it. Yes, it is absolutely good to change history here so that the Allies win, but there are plenty more times when changing history would be good as well. Why stop at changing history so my timeline doesn't exist anymore? Why not go back and save the people colonized by the British? Or the people who died in the numerous wars before WW2? The Doctor's going after her "paradise built on the back of genocide" rings holo when he's not willing to stop any other genocide. Only because in the history that he's familiar with, the Allies won WW2 so that's the only genocide he's willing to stop. It makes me look forward to Klein's further appearances if she calls the Doctor out on his hypocrisy even though, you know, she's a literal Nazi.

Ace's B plot is definitely less interesting as it's just her planning an escape attempt and getting ratted out by one of the other prisoners. And getting harrassed by David Tennant. It's not bad at all, just not as interesting as the meat of the time travel discussion.

Ultimately they end up leaving Klein in the 1940s, which could potentially have devestating effects. It's interesting that, when her timeline gets aborted, she doesn't cease to exist. She's a person from a timeline that no longer exists living in a time before her time. That could potentially be dangerous to to the war effort as well. Maybe if she positions herself well enough, she could help the Nazis win. Or maybe she could just get herself shot. We don't know. I'm sure we'll find out later when she's brought back.