On this episode of Supernatural…
Dean is tracking down a witch when he gets hit by a spell that makes him forget.
Sam finds his brother and calls in Rowena to help.
She reveals that an ancient family of witches have a special spell book that can break the spell before Dean forgets everything and dies.
Sam is captured after finding the family.
Rowena stops by, but she is nearly killed by one witch.
Dean shows up and manages to kill the remaining two witches.
Rowena is able to use the book to cure Dean.
Rowena tries to take the book, but Sam knows and gets it from her. He says they owe her one.