The Secret Circle.

After her mother dies in a fire, Cassie Blake moves in with her grandmother in the small town of Chance Harbor, Washington. As she gets to know her high school classmates, strange and frightening things begin to happen. They are all descended from powerful witches, and they've been waiting for Cassie to join them and complete a new generation of the Secret Circle. What they don't yet know is that darker powers are at play and that Cassie's mother's death might not have been an accident.