The Vessel” — (9:00-10:00 p.m. ET)

LUCIFER (AS CASTIEL) SENDS DEAN BACK IN TIME – 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. John Badham directed the episode written by Robert Berens (#1114). Original airdate 2/17/16.

The bad news for Collins is that as complicated as his new role already is, it gets even more complicated this week, when Lucifer — or Cassifer/Lustiel, if you prefer — sends Dean back in time to WWII and then spends the episode hanging out with Sam in the bunker.

“This is the Nazi time-travel submarine insanity episode,” Collins says. “It’s going to be good. And my character particularly in this episode is going to be completely and utterly schizophrenic. I will be pretending to be somebody pretending to be somebody pretending to be somebody. It will be layers and I’m sure that I’ll lose the thread at some point as a performer so I’m a little nervous to see it,” he says with a laugh.

But more than anything, Collins says this is one of those Supernatural episodes he won’t soon forget. “I gotta tell you, I would say maybe twice a year I’ll read a script and I’ll be like, ‘No, really they’re doing that? That’s awesome. This is fantastic. I love this show.’ And this is one of those episodes. It’s a killer concept and it’s going to be a great episode.”