In the series premiere, Cassie Blake’s (series star BRITT ROBERTSON) world is turned upside down after her mother dies in a mysterious accident, forcing Cassie to move in with her loving grandmother Jane (series star ASHLEY CROW) in the small town of Chance Harbor, Washington. While trying to adjust to her new life, Cassie is quickly befriended by Diana Meade (series star SHELLEY HENNIG), a sweet-natured classmate who offers to show her around and introduces her to mean-girl Faye (series star PHOEBE TONKIN), Faye’s sidekick Melissa (series star JESSICA PARKER KENNEDY) and Cassie’s next door neighbor Nick (series star LOUIS HUNTER). Things get complicated when Cassie meets Adam (series star THOMAS DEKKER), Diana’s boyfriend, with whom she feels an instant and powerful connection.

In an effort to distance herself from the Circle and establish a normal teenage life in Chance Harbor, Cassie befriends Sally Matthews (recurring guest star Logan Browning - Meet the Browns, Bratz), a non-witch. Concerned their powers are getting out of control, Diana pushes everyone to bind the Circle, but Faye is thrilled with the increase in her powers and refuses to participate, while Melissa flirts with Nick despite Faye's warnings. Meanwhile, Adam fights his growing feelings for Cassie, but circumstances continue to throw them together, forcing Cassie to make a decision.

A cute jock named Luke (recurring guest star ZACHARY ABEL - Make It or Break It) asks Cassie to the school dance, and after watching Adam spend time with Diana at the boathouse, she accepts his offer. Meanwhile, Melissa sees the dance as an opportunity to get closer to Nick. Faye, on the other hand, has no plans to go and remains focused on finding a way to control her powers. Dawn discovers someone from their past, an intense man named Zachary (guest star DAVE BAEZ - Dexter), is in town asking questions about the Cassie and the Circle, so she asks Charles to keep an eye on him.

Cassie looks up an old friend of her mother’s named Heather Barnes (recurring guest star CAMILLE SULLIVAN Shattered) and discovers she has been in a catatonic state since the night of the fire 16 years ago. Feeling guilty that her mother and her Circle may have had something to do with Heather’s current state, Cassie tells Diana that she wants to use magic to help Heather. Diana refuses to help, but Faye is more than happy to conjure up a spell for a price.

Torn between her loyalties to the Circle and her family, Cassie wrestles with the secrets she must keep from her grandmother. Nick is thrown for a loop when Melissa adopts a new attitude and enlists his help to track down her family's Book of Shadows. Faye is also recruited, but isn't happy about being the third wheel. Meanwhile, Diana craves some alone time with Adam and arranges a date night so they can rekindle the spark in their relationship, but all six youths are brought together to fight off a dark force that threatens to destroy the Circle from within. Completely unaware of the new danger encroaching on their children, Dawn joins Charles aboard his boat to further their plans for the Circle, but is surprised to find that Charles may have more than business on his mind.

When a mysterious young man named Jake (recurring guest star CHRIS ZYLKA - Shark Night 3D, 10 Things I Hate About You, upcoming The Amazing Spider-Man) shows up in Chance Harbor, he learns a lot has changed since his last visit to the town. For one, the girl he left behind - Faye - has discovered she is a witch and has plans to get even with this handsome guy who broke her heart. To complicate things further, Jake sets his sights on the alluring Cassie, much to Adam and Faye's dismay.