Infodump time!

For people not familiar with the Teen Titans cartoon, here is the abridged story of Terra.

First of all, the Titans are a group of teen superheroes living together in a giant T-shaped tower overlooking some city in California. Don't ask me how they get away with this. They just do. Anyway, Terra is another girl with freaky powers they meet one day.

She instantly hits it off with most of the team, especially Beast Boy, but Raven and Robin have their reservations. She spends some time with them, but it quickly becomes apparent that she has trouble controlling her earth-moving powers. Slade, the main villain, preys on this weakness and convinces her to become his apprentice to become stronger. He convinces her that once they find out she has trouble controlling her powers, they will abandon her. Needing to feel wanted, she follows him after some hesitation.

She ends up following Slade and betraying the team, engaging in some bitter fights with them as she almost destroys the city. She realizes what she's doing and repents for her sin too late though-the city is saved, but she is trapped in stone.

Oh yeah, and then there's the series ending in which she inexplicably appears alive but doesn't seem to remember having powers or being a Titan. It's left open whether she actually doesn't remember or is pretending not to.