The thing about "Colditz" is that it's really a not-very-good audio. It should have been fantastic. In reality, Colditz is a castle in Germany which was used as a prison during World War II, housing prisoners of war who had escaped multiple times from other concentration camps; thus, it had the reputation of being very high-security and very intolerant. The story, then, follows the events after the Doctor and Ace land there in the TARDIS. They very quickly get separated and aren't reunited until near the end of the story. The Doctor is taken away from Colditz by a Nazi scientist named Elizabeth Klein, and this storyline is intriguing and engaging. (I won't spoil it here, though I will say that Dr. Klein appears in more audios; that should tell you that the story they created for her is worth it.)
The problem was with the Ace side of the story. She spends the entire story in Colditz as a prisoner, trying to escape to find the Doctor, and this should have been gripping. A female Brit as a war prisoner in the worst prison in the Nazi system? What an opportunity to deal with the horrors of war and gender differences! But they wasted every moment of it. After listening to the first bit of it, I remember thinking, "What, did the writer research Nazi concentration camps by watching Hogan's Heroes?" because that's exactly what it felt like. It didn't help that the background sound effects of the prisoner's mess hall sounded like a party, but even the dialogue was terrible. The prisoners treated trying to escape as a game. They mouthed off to the guards. They laughed and joked constantly. And Ace... She continuously mouthed off to the guards, insulting them, refusing to do things, etc., with no repercussions. It wasn't that they were shying away from violence - at one point, Feldwebel Kurtz tells Ace that he's going to visit her that night in her cell and rape her - but they simply chose to make it a light-hearted atmosphere with random injections of horror, and this ruined it. You never got the impression that Ace was more than slightly inconvenienced by being in a concentration camp.
Thus, I decided that with this story, I wanted to fix that a little and give the audio the gravity and tension that it needed. Ace didn't take Kurtz's threat seriously at all, but here, she does.
While Ace is the person that appears in my story, it's at least half about Kurtz, who was my favorite character in the audio. It's not because I liked him, mind you. I don't think it's possible for anyone to like him; he had absolutely no redeeming qualities. What I loved about him was that they wrote him so that though he spent most of the audio being cruel and unreasonable, you could see exactly who he was, what he wanted, and why he did the things he did. On the surface, he seemed to be simply evil and sadistic, but it was very apparent that he was ambitious, trying to rise to the top of the Nazi hierarchy, but not at all skilled or intelligent. Thus, his attempts to assert his authority and demonstrate his worth became more and more irrational as he failed to impress his superiors, was being ignored by them (even when he was right - in the manner we often see in DW, Kurtz starts to realize that something unearthly is going on and tries to battle it, and no one believes him) and eventually stripped of his power, and even started to lose control of his prisoners. His character development, though it was more of a devolution rather than growth, was fascinating, up until his rather horrible end. He's probably pretty unique in the history of DW in being directly killed by the TARDIS. (And it's not a nice death; in fact, in a different audio, years later, Ace refers to his death as the most horrible thing she'd ever seen.)
I'm not sure that I'll ever listen to "Colditz" again - too many other wonderful stories to experience and/or revisit. I might just to listen to the Doctor's and Klein's storyline, but I probably won't revisit the Ace side (no matter how good Kurtz's performance was; there's no way it could have been anything less than brilliant *wink*). I just prefer to remember the audio as I like to picture it in my head. (Hm, maybe I should do a fan rewrite. Yeah, like I'd ever devote that much time.)