O Brother, Where Art Thou?

O Brother, Where Art Thou is the 9th episode of Season 11. It aired December 9th, 2015.

Summary
AMARA UNLEASHES HER POWER UPON THE WORLD — Amara (guest star Emily Swallow) unleashes her power on the local townspeople as she issues a shocking challenge. Dean (Jensen Ackles) tries to better understand the hold Amara has on him, while Sam (Jared Padalecki) and Crowley (Mark Sheppard) come up with a plan that could have disastrous consequences.

Main Cast

 * Jared Padalecki as Sam Winchester
 * Jensen Ackles as Dean Winchester
 * Mark A. Sheppard as Crowley

Recurring Cast

 * Emily Swallow as Amara
 * Mark Pellegrino as Lucifer
 * Ruth Connell as Rowena

Features Supernatural Beings

 * The Darkness
 * Angels
 * Archangels (Lucifer)
 * Demons (Crowley)
 * Witch (Rowena)

Trivia

 * Lucifer re-appears in this episode
 * Lucifer shows red eyes just like in the new Fox's show Lucifer