In honor of the holiday, Faye and Melissa throw a girls only anti-Valentine’s Day slumber party for themselves and fellow witches Diana and Cassie. But the night gets wilder than expected when Melissa offers Diana some mood altering “Devil’s Spirit” and the first person Diana loosens up around is Lee, who crashes the party to help Faye achieve her own power. Meanwhile, Cassie is forced to turn to Adam and Jake after she becomes haunted by the spirits of some vengeful witches.

Cassie enlists the Circle's help when she receives a frightening warning about the witch hunters' return. At the same time, her true feelings for Adam and Jake surface during a birthday party that Ethan decides to throw with the help of Diana. Meanwhile, Faye and Melissa take their inner power to a chilling new level when they try a little of Lee's "Devil's Spirit."

Jake returns to Chance Harbor to warn Cassie that unless they find out how her father was killed in the boat fire 16 years ago, she'll meet with the same death. He suggests an extremely dangerous method to finally uncover what happened on that fateful day, but Adam and Diana suspect he has ulterior motives. In an effort to usurp the other, both Charles and Dawn try to get Ethan on board as an ally. Faye gets trapped in a dangerous situation when one of Lee’s friends, Callum stops by the shop.

Cassie asks Adam for help when she wants to look into her father's past, and their search leads them to an eerily familiar place. It also rekindles an old flame when Adam, thrilled to be spending time with Cassie again, asks her to the Fire and Ice dance. But because of her friendship with Diana Cassie is forced to give a surprising response. In an effort to be a better father, Ethan offers to chaperone the dance, much to Adam's dismay. Faye asks Lee to help her with a spell that would grant her individual magic. Unfortunately, the spell has some terrifying side effects that nearly destroy the Circle.

Cassie turns to Adam when she uncovers a secret about herself that she needs kept from the rest of the Circle, including Diana. Meanwhile, Diana is thrilled when her grandmother Kate drops in for a visit, but Charles is suspicious of his mother’s motives after Kate takes an unusual interest in Cassie. Meanwhile, Faye recruits a mysterious stranger named Lee to help her with a spell that could change the balance of the Circle forever.

Cassie and Jake look into her father's side of the family, hoping to discover more about her lineage and why she has powers separate from the Circle. Meanwhile, Adam becomes protective of Cassie when Faye reveals that Jake might be hiding something dangerous from them. At the same time, Adam's equally concerned when Melissa's cousin Holden comes to town and catches Diana's eye. A power shift forms between Charles and Dawn that threatens to destroy their plan.

After not hearing from her grandmother for a couple of days, Cassie becomes concerned and wants to go look for her. Diana decides the entire Circle should go in case Jane is in trouble. She also invites Jake along, much to Adam's dismay. A storm turns the day trip into an overnight excursion, so Faye suggests a little game of Truth or Dare to liven up the evening. However, things take a horrible turn when Faye is forced to reckon with someone from her past.

Deciding the Circle needs to have a little fun, Faye convinces Cassie to throw a big Halloween party. Intent on wooing Jake back, Faye goes all out on her Halloween costume. After a fight with Diana, Adam turns to Cassie for advice. Meanwhile, some dangerous, uninvited guests set their sights on the Circle.

When Jake, a mysterious young man, shows up in Chance Harbor, he learns a lot has changed since his last visit. For one, the girl he left behind, Faye has discovered she's a witch and has plans to get even with the handsome guy who broke her heart. To complicate things further, he sets his sights on the alluring Cassie, much to Adam and Faye's dismay.

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 is craving some alone time with Adam and arranges a date night so they can rekindle the spark in their relationship, but all six of them 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.

Cassie looks up an old friend of her mother's named Heather Barnes 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.

A cute jock named Luke 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, is in town asking questions about the Cassie and the Circle, so she asks Charles to keep an eye on him.

In an effort to distance herself from the Circle and establish a normal teenage life in Chance Harbor, Cassie befriends Sally Matthews, 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.

Cassie Blake's world is turned upside down after her mother dies in a mysterious accident, forcing Cassie to move in with her loving grandmother Jane in the small town of Chance Harbor, Washington. While trying to adjust to her new life, Cassie is quickly befriended by Diana Meade, a sweet-natured classmate who offers to show her around and introduces her to mean-girl Faye, her sidekick Melissa and Cassie's next door neighbor Nick. Things get complicated when she meets Adam, Diana's boyfriend, with whom she feels an instant and powerful connection. Upon meeting one of her mother's childhood friends, Dawn Chamberlain, the school principal and Faye's mother, Cassie begins to wonder why her mother never spoke of her hometown. When strange and dangerous things begin to happen, Cassie's new friends are forced to tell her their secret - they are all witches and her arrival will complete the Circle. However, the Circle has not been drawn together again by chance - Diana's father, Charles Meade has plans of his own for the group.