Castiel (Misha Collins) finally got his grace back, but it does not mean that all his problems are through, and he will need the assistance of the Winchester brothers to help him defeat a murderous assassin in the upcoming episode of "Supernatural" season 10.

But Castiel and the Winchester siblings will not be prepared to find out who the ultimate monster is, which happened to be a smart mouth teenager, who will call Dean "old". This definitely hurt his feelings, but the audience would definitely enjoy seeing Dean answer her back with a very pained "How dare you?"

Meanwhile, Castiel will feel guilty after everything that he did with the Novak family. He will try to make up for it by attempting to reunite Claire and her long-lost mother Amelia, but things will not work exactly as expected.

The official synopsis for the episode titled "Angel Heart" reads:

"When Claire Novak (guest star Kathryn Love Newton) gets a lead on her mother, Amelia (guest star Leisha Hailey), who has been missing for years, Castiel asks Sam (Jared Padalecki) and Dean (Jensen Ackles) to help her. Castiel feels guilty for what he did to the Novak family and wants to make amends by reuniting Claire with her mom. However, when they find out what took Amelia, they realize there is a chance Claire may not get her happy ending."

Will Castiel succeed in his plans for the Novak reunion and find out where Amelia had been staying all these years?

This could be just one of the very few episodes wherein the Mark of Cain will not be tackled, and their constant problem with Rowena's (Ruth Connell) disappearances. But it does not mean that the episode will not be packed with action sequences that the long-running series is known for.

Supernatural Season 10 episode 20 airs on Wednesday, April 29, on The CW.