Ep 20. Angel Heart

In Supernatural season 10 episode 20, titled "Angel Heart," the Winchesters take on a case that involves Claire Novak, who first appeared in season 4 as the daughter of Jimmy Novak, who was a vessel for the angel Castiel. Claire has been living on her own and getting into trouble since her father's death, and the boys team up with Castiel to help her.

The episode starts with the boys finding Claire in a bar after tracking her down. They try to convince her to come with them, but she initially refuses and tells them to leave her alone. Later on, they find out that her friend has been murdered. Claire tells them that she has been looking for her mother, who abandoned her when she was young, and her search has led her to a woman named Amelia, who took her in and was like a mother to her for a while.

The trio then meets with Amelia, who tells them about a supernatural force that took over a young girl's body, which is what caused the murder. She also reveals that Claire's mother had been possessed by the same force and had killed herself. The boys and Castiel believe that the supernatural force is an angel, and they think it might be responsible for the recent killings.

Claire is determined to find out more about her mother, and the boys and Castiel agree to help her. They come across a group of angels who are led by Hannah, who tells them that the angel that possessed Claire's mother is an Enochian angel named Ishim. Ishim was one of Castiel's closest friends when he was an angel, but he has been corrupted and is now responsible for the murders.

The boys and Castiel confront Ishim, but the angel refuses to leave Claire's body. He tells them that he had a love affair with Claire's mother and had been trying to find her ever since she left. Ishim believes that Claire is the key to finding her and is willing to do anything to get what he wants.

The group comes up with a plan to exorcise Ishim from Claire's body, which involves using a ritual that requires the blood of a powerful angel. Castiel volunteers to give his blood, but the process is risky, and there is a chance that Ishim could overpower them and kill Claire.

The ritual is successful, and Ishim is exorcised from Claire's body. However, just as they think they are in the clear, they are attacked by a group of angels who are loyal to Ishim. The boys and Castiel fight them off, but Hannah is killed in the process.

In the end, Claire decides to leave with the group and continues to search for her mother's whereabouts. The episode ends with the boys discussing how they have to deal with the angels now that they have become a bigger threat.

"Angel Heart" is a character-driven, emotionally charged episode that explores themes of loss, family, and redemption. It is a great watch for fans of the show who are invested in the characters and their relationships. The writing is strong, and the performances by the cast are superb, making it an episode that is both thrilling and heartbreaking.