Harry is set to go back to Hogwarts, but some strange stuff is going on, mainly a house elf named Dobby trying to keep him from getting back. Well, Harry gets back, and strange stuff doesn't stop. There are mysterious messages being written, and people (and cats) being petrified. What's not helping the matter is the fact that Harry is hearing voices that no one else can. Throw in the legend of the Heir of Slytherin and the Chamber of Secrets, and that people have discovered Harry is a parselmouth (can speak to snakes), and it's looking like a pretty rough year for Harry. Well, when a mysterious diary pops up, then just as quickly goes missing, the plot thickens. And now there's a big problem: A note saying that someone is taken into the Chamber of Secrets... and it's Ginny, Ron's little sister. Now it's up to Harry, Ron, and Hermione (no surprise) to go and save the day. But can they do it?
Well, if you've read the book or seen the movie (or can make a guess based on the 5 books that come after it), you'll know that they can do it. Harry once again comes face-to-face with Voldemort, though this time a memory of his former self. This came about through an enchanted diary, the depth of its magic goes far deeper than at first expected. This diary came into the possession of Ginny Weasley, and she started using it. What was so special about this diary is that it could respond to what you wrote in it, so Ginny started to write all of her secrets in it. The more she poured into the diary, the more Tom Riddle (who would become Lord Voldemort) was able to make himself stronger, till finally he could pretty much control her, and bring himself out of the book. He was the Heir of Slytherin, and had opened the Chamber before, and had done it again. Now Harry needs to kill a Basilisk, destroy the diary, and save Ginny's life. This is a frightening thing that happened to Ginny, and it's fortunate that something like that couldn't happen to us... right?