As I said before, this episode could've been combined with the previous one without losing much footing. But I can forgive that, since then we wouldn't have the great Russian roulette scenes.
Yes, this episode is filler; the prison riot scenes didn't HAVE to be shown, but if it has to happen, then it has to happen. And what would be the point of having Jack resort to such a ridiculous escape plan in the first place? No, the riot scenes instead constitute a self-contained crisis that Jack and Ramon must find their way out of before continuing with the main virus threat. It's pretty much the basis for this hour.
Meanwhile, Palmer starts his presidential debate with John Keeler, which…whatever.
CTU goes through its own stuff, which is mainly pinpointing Kyle's location, but also with their discovery of Jack's heroin addiction. Darkly funny scene where Chloe tells Kim all about it.
Strangely enough, the Russian roulette game helps to build some character development for both Jack and Ramon. Specifically, it helps to define what hard-headed badasses these guys are. While we kinda knew that already, what with the first two seasons and the pen stabbing earlier, it's a welcome piece of filler, and it makes for quite an improvement over the last few episodes. The big shootout later is just a sweet bonus.
The wimpy guard shooting himself.