The whole gang-Anna, Elsa, Kristof, and Olaf-are back to save Arendelle. They are on a quest to find the truth about an enchanted forest, their parents, and the origins of Elsa's wintery powers.
This film is not as good as the original but did you really expect it to be? Judging the movie on its own merits, it's good. The storyline is good. The best parts are the references to Hans from the first movie and Olaf's summary of Frozen's plot. Make sure you stick around after the credits!