The Secret Circle is actually a series by L.J. Smith, author of The Vampire Diaries.
In writing 101 most people learn that a story has a beginning, middle and end. The Secret Circle does provided you read the entire series as one work. I don't think the separate books, really work as stand alone books! This series didn't do so well when it was originally released as three books. It was re-released with The Vampire Diaries in the midst of the Twilight mania. This time it was released as four books in two volumes. In book 1, The Initiation, Cassie (the main character) meets an attractive guy on a beach and helps him avoid conflict from another set of boys. She is then forced to move to the home of a grandmother she has never met and the kids at her new school are anything but nice to her. She is befriended by a popular girl and due to some unfortunate circumstances her luck begins to change. Adam, the hot guy from the beach, shows up near the end of the book. He is Cassie's popular protector's boyfriend and was gone looking for things for the The Club, the coven of witches Cassie has just been initiated into.
The Club has a mix of characters some pure, some purely evil. In the next two books a forbidden romance develops between Cassie and Adam and they skirt around to avoid hurting Diana, Adam's girlfriend. Aside from this some really dark forces are developing as well. Cassie's initiation into The Club happened only because the younger sister of two club members who was supposed to be initiated was killed. This perpetrator was originally expected to be someone outside of The Club who opposed witch craft and disliked club members. But as the story unfolds in the The Captive Part I, The Captive Part II and The Power the force behind that girl's death seems to be much darker and more powerful than a single mortal. The Club, through all of its struggles, takes on this darker force in an effort to save basically everyone.
When read together like this, The Secret Circle paints a complete picture and tells a complete story. It should never have been sold as a series. Maybe, I'm yet to be published because I write to send a message and tell a story rather than to make a million dollars. But I hate that YA publishers and writers seem to consistently make series out of things that aren't in an effort to sell more books. Twilight was originally supposed to be two books, in which the wolves played a minor role, the Cullens defeated James and Victoria and Breaking Dawn ended essentially the same way. When it did so well in sales, all of the sudden Edward needed to leave Bella and this awkward friendship/romance needed to disregard all boundaries between Bella and Jacob resulting in an extra two books with a series that ends the same way. (And I'm more okay with that since each book had a beginning, middle and end)! Skinned was about a copy of a human brain placed in an artificial body struggling to determine whether or not it was human. It wasn't. The book ended. But then two sequels popped up.
The Secret Circle is about a group of kids many missing one or both parents struggling to become who and what they are, and dealing with the responsibility that entails. It's entertaining--a page turner. The whole series is 785 pages and tells one story. It should have been one book. In honesty, the story was good enough that I probably will by both volumes of The Vampire Diaries, although I feel certain in the end I'll have the same complaint. But I don't appreciate publishing companies milking me for dimes by selling a normal size book in two volumes to increase profits.