The Executioner's Song

The Executioner's Song is the 14th episode of Season 10. It aired on February 17th, 2015.

Summary
THE RETURN OF CAIN — Dean (Jensen Ackles), Sam (Jared Padalecki) and Castiel (Misha Collins) deal with Cain’s (guest star Timothy Omundson) return. Crowley (Mark Sheppard) and Rowena (guest star Ruth Connell) continue to grow closer but when Crowley bails on plans with his mother to help the Winchesters, Rowena lets him have it.

Characters

 * Dean Winchester
 * Sam Winchester
 * Castiel
 * Crowley
 * Cain
 * Rowena

Featured Supernatural Beings

 * Demon
 * Knight of Hell
 * Angel
 * Witch

Trivia

 * The title is a reference to the 1979 book and the 1982 movie of the same title about the killer Gary Gilmore.
 * When Castiel and Cain met at the graves of Cain's victims, Castiel and Cain are definitely aware of each other and may have had personal history with one another.
 * After the episode, Robbie Thompson tweeted a hashtag - #CainLives - which quickly gained the attention of fans and Timothy Omundson himself. Whether or not it is true is yet to be seen, but as we don't clearly see Dean finishing Cain off, the door is yet to be closed.