Harry comes across the blank book in the girls' bathroom at exactly the moment when he needs information the most. Who opened the Chamber of Secrets last time? When did it happen? And what exactly killed the student?

Along comes Tom Riddle's diary to tell him everything he needs to know. Even if he doesn't much like the answers. Hagrid opened the Chamber of Secrets fifty years ago and his giant pet spider, Aragog, killed a fellow student. Bummer.

But it all seems legit. After all, this nice, clean-cut prefect named Tom Riddle just showed Harry so it must be true, right?

Like Ginny, Harry is seduced by the power of the diary pretty easily. He is convinced by Tom Riddle's lies and accepts them. Just take a look at this exchange between Harry, Ron, and Hermione:

HARRY POTTER: It was Hagrid. Hagrid opened the Chamber of Secrets fifty years ago.

HERMIONE GRANGER: It can't be Hagrid. It just can't be.

RON WEASLEY: We don't even know this Tom Riddle. He sounds like a dirty, rotten snitch.

HARRY POTTER: The monster had killed somebody, Ron. What would any of us have done?

Think about it. Harry is defending Voldemort here. That's how bewitching this diary actually is.

Though Harry initially trusts the diary and Tom, but eventually learns that appearances aren't always what they seem. This may look like an innocent little book filled with magical information, but it's something a whole lot more sinister. And Tom Riddle might appear to be a fine, upstanding young Hogwarts student, but he's actually a young homicidal maniac in disguise.

Just goes to show you that you can't judge a book by its cover.