"The Closer" season finale recap: "Waivers of Extradition"

I know the season finale of TNT's "The Closer" aired a few days ago, but I didn't get a chance to watch it until last night, and wanted to just say a few things about the episode and this season.
First, the season finale, "Waivers of Extradition," was a pretty strong episode. I always like when the scripts give Kyra Sedgwick's Brenda an equally strong-willed character to bump up against, and this time we got Xander Berkley (George Mason from "24"!) as a tough Texas lawman who -- shocker!-- actually wins a battle of wills with Brenda, getting her to release a creepy serial killer to Texas so he can face the death penalty. I also thought it was interesting that Brenda would rather see someone like this die than win a power struggle. This goes to her strong sense of vengeance, which we've seen before. She's set people up to get killed, remember (I'm thinking particularly of the young mobster who trafficked in women in season one. She let slip to his bosses that he was an FBI informant, and he disappeared, if I recall correctly). It's odd to make a character so blood-thirsty -- especially a woman, and especially one who's painted not an anti-heroine, but as a true heroine, all be it a slightly flawed one.
It's bold, refreshing, and gives you something to think about in this otherwise old-fashioned, briskly entertaining series.
I also wanted to mention how impressed I was with the storyline about Brenda's niece. We probably knew that, once her cat died, Fritz would see this as opening to broach the subject of kids. Instead of a hackneyed series of pregnancy debates, we saw Brenda get some practical parenting experience, looking after her troubled young niece. Her efforts were mixed. I, personally, don't think it's a good idea to use a teen you're supposed to be looking after in a murder investigation.
But, on the plus side, her time with Brenda and Fritz seems to have given niece Charlie some focus, purpose and confidence. She has a greater respect for life, now that she knows how awful life -- and death -- is for many people.
I should mention that Charlie was played by Kyra Sedgwick's real-life daughter, Sosie Bacon, who was actually quite good. This sort of casting-by-nepotism doesn't always work out (remember Autumn Chiklis as Vic's daughter on "The Shield?"), but this time, it did. The mother and daughter worked well together, playing aunt and niece. That scene at the end of the finale -- when Brenda realizes that she doesn't really want Charlie to leave, but that she has to let her go -- was tender, moving and not overplayed.
All in all, a good episode and a good season.