The Vampire Diaries The Vampire Diaries

What turned The Vampire Diaries' Katherine Pierce (aka Katerina Petrova) into a cold-blooded killer? Nina Dobrev (Elena/Katherine/Katerina) says we'll find out on the November 11 episode when the action flashes back to 1490s Bulgaria.

"We find out how she became a vampire and what led her to become the person she is today — a selfish, maniacal woman who only looks out for herself," says Nina, who was born in Bulgaria and speaks Katherine's native tongue. How she's turned is a big secret, as is the identity of a new menace we'll meet from the same era, who will journey to present-day Mystic Falls.

"This villain has ties to the deep, deep past of the vampire legend," teases executive producer Julie Plec. "And then in our last episode before the holidays [December 9], we'll finally see poor Tyler Lockwood's torturous transformation into a werewolf."

Subscribe to TV Guide Magazine now!