"The Southern Raiders" was a story that fans have been looking forward to since "The Puppetmaster."  Once the concept of bloodbending was introduced, it was clear that it would come back to haunt Katara at some point, particularly with her attitude become much more unforgiving in recent episodes.  Luckily, this story is one that lives up to expectations.

Starting off the episode with a fight between Zuko and Azula was an interesting choice for a Katara-centric tale.  On the surface, it might not seem to have all that much to do with the rest of the episode.  However, aside from giving Zuko the opportunity to save Katara's life and thus set the plot in motion, it's a quiet nod to the episode's overall theme of the death of one's enemies.  Despite being the least idealistic member of the Gaang, there is clear regret in Zuko as he watches Azula plummet to her potential death.  While he knows the enemy better than anyone, not even he can find reason celebrate in such a win.  It’s a subtle but strong statement.

Justice versus vengeance isn't exactly typical children's show material.  However, Avatar handles the topic well, thanks in no small part to the fact that Katara herself is still fairly young and not really capable of the type of bloodthirsty cruelty that she thinks she is.  While "The Puppetmaster" was an excellent episode, it did raise the question of why Hama didn't simply bend the moisture out of people rather than just controlling them.  The most obvious answer is that you can't really show people being murdered by vacuum pack on a kid's cartoon.  However, Katara's use of bloodbending, while certainly brutal, is believable as the extent that she is able to go.  It remains (reasonably) kid-friendly without sacrificing believability for older viewers who know better.

As interesting as Katara's decent into darkness is what has become of her enemy.  The soldier who haunted her memories for years is a pathetic broken man when she finds him, a shadow of her childhood nightmare.  During their confrontation, he is the one who is terrified of her.  She is the one with all the power, but of course makes the decision not to use it in the end.  There was never a real question about how the situation would end, but the audience did get a good look at how hate and rage can tear a person apart even without Katara crossing that line.

It would seem that Suki and Sokka got the memo that this would be a more adult-oriented episode than most and decided to take advantage of it.  The little setup for that liaison was a welcome bit of comedy in a rather dark story.

In yet another nod to the acknowledgment of the show's plot devices, it was nice to see the show hang a lampshade on the whole "Aang and friends each take an important journey with Zuko, allowing them to work out their issues and him to quickly bond with the group before the final battle" bit.  On the other hand, the almost ham-handed dismissal of the extra cast members who have pretty much been offstage since they joined the group was a little disappointing.  Why have them join the Gaang in the first place if they weren't going to play an important role?  Or any role for that reason.  Hopefully they will reappear for the final arc and do something interesting.