We already knew from a long time that Nickelodeon was working on Book 4 of The Legend of Korra, but who would have thought it would come this early. It wasn't too long ago when Season 3 ended, and now we have a trailer of Season 4.

The new season is called The Legend of Korra: Balance, and from all indications, it appears Korra will set out to bring balance to the world, again. We have no idea who the big bad villain is, or whether or not he or she showed up in the trailer.

What we do know is that Korra cut her hair and the kids have grown up a lot. Of course, this story is set three years after Season 3, so everyone has become older and during that time a new enemy has risen from the ashes.

The trailer shows quite a lot; we even get to see one guy with twin blades, which makes us wonder if he's the son of Sokka. Over the last three seasons of Korra, we didn't get to learn a lot about his life after The Last Airbender. However, the writers did mention that Season 4, which is the final season, will answer all questions.

We have to say though, in several scenes, Korra looks pretty depressed, which makes us wonder what has been going on in the past three years and why she's looking so torn apart.

At the end of the trailer, a big surprise scene happened. It appears as if Korra found Toph, but we did not get to see her face. It is not clear what state Toph was in, but from the look on Korra's face, things don't seem to be going quite well for the blind earth bender who invented metal bending.

For Toph to have lived so long, something supernatural must have happened to her, or maybe she ascended to another form of earth bending? We can't be sure. One thing is certain: Toph is alive and all hell is going to break lose when Season 4 kicks off.

The Legend of Korra: Balance will kick off on Oct. 3 on Nick.com and the Nick mobile app. The show will no longer air on Nickelodeon TV, something that has been going on since the third season.