The Vessel

The Vessel is the fourteenth episode of Season 11. It aired on February 17th, 2016.

Summary
Hoping to find a weapon powerful enough to defeat Amara (guest star Emily Swallow), Dean (Jensen Ackles) convinces “Castiel,” (Misha Collins) who is still Lucifer, to send him back in time to the last reported sighting of the Hand of God. Lucifer sees the potential in getting his hands on this weapon so goes along as Castiel and sends Dean to 1944 to the fated submarine mission that sunk the Hand of God. Meanwhile, continuing his charade with Sam (Jared Padalecki) while they wait for Dean’s return, Lucifer plans his next move.

Main cast

 * Jared Padalecki as Sam Winchester
 * Jensen Ackles as Dean Winchester
 * Misha Collins as Lucifer/Castiel
 * Mark Sheppard as Crowley

Guest cast

 * Weronika Rosati as Delphine Seydoux
 * Grant Harvey as Petey Giraldi
 * Bethany Brown as Simmons
 * Taylor St. Pierre as Galley Cook
 * Richard Stroh as Befehlsleiter (Nazi Command Leader) Gumprecht

Continuity

 * Sam and Dean discover Lucifer's possession of Castiel.
 * First successful use of the angel banishing sigil since I Think I'm Gonna Like It Here. It is also the first time the angel banishing sigil was used on an archangel.
 * Marks the first appearance of a member of The Thule Society since Everybody Hates Hitler.
 * Crowley's fate after The Devil in the Details is revealed in this episode.

Trivia

 * The last episode to display time travel was King of the Damned, when Abaddon went back in time to retrieve Gavin MacLeod.
 * This episode marks the fourth time Dean has traveled to the past. The previous time was in episode Time After Time.
 * This is the second occurrence of time travel being employed to retrieve something necessary from the past. The first was in Frontierland to get the ashes of a phoenix, as the species had died out years prior.
 * Castiel using Bobby's soul to power up in Frontierland is referenced.
 * Delphine's phrase "the Men of Letters send their regards", is a likely reference to "the Lannisters send their regards" from HBO's Game of Thrones.

Quotes
Sam : Lucifer. Lucifer : In the flesh.
 * Lucifer : It's just, I don't need you anymore. I mean, Dean's the one with the link to Amara. Why have I been trying to spare you? Maybe it's because you're like the girl who kept turning me down at the prom. [slams Sam into a pillar] I will touch your soul, just because you asked so nicely. And I'll use your spell to blast through the warding and retrieve Dean and the, um, Hand of God. And then when Dean comes back and he finds this place decorated with your guts, I will tell him the truth, Sam. I'll just say, "Dean- [switches voice] Dean... he knew the risks, but he wouldn't take no for an answer."