The Secret Circle Season 1 Episode 4 (10/06/11)
Cassie, Adam and Diana were trying to find out information about Heather Barnes; they found out that Heather had a cousin that lived close by. Adam and Cassie went to see the cousin, Adam who showed them Heather.
Heather was in a catatonic state and had been for 16 years. Back at her house Cassie showed Adam her book of shadows and explained her mother had put the spell on Heather. Adam and Cassie began to prep a reversal spell when Diana told them they didn’t know enough and they had to stop.
Adam stopped but Faye offered to help Cassie if she would let Faye look at her book of shadows. Faye and Cassie snuck back out the visit Heather and attempted to the spell which appeared to have no effect.
After they left, the spell did take effect and Heather smashed her cousin through a wall and went to Cassie’s looking for her mother. Heather was able to relay a little information before the demon that was inside her took hold and wreaked havoc. As demon-Heather ran from the house she was hit by a car and killed.
Cassie admitted to Adam she didn’t know enough, the demon in snake form had caught a ride with Nick but planted itself in Melissa.