Thats just how it works.
But Im happy to report that my worry was misplaced.
And thats why she messed up the spell on purpose so that Lucifer could trap Sam inside the cage.

Credit: Katie Yu/The CW
As Lucifer puts is, Groupies, theyre always so eager.
Lucifer claims that hes not going to torture Sam.
After all, That was so five years ago.
With that, Sam acts fast, kissing her before he can say anything else about Aztecs.
And THAT is the kind of action that Lucifer loves.
Sam used to be a hero.
Heck, he beat Lucifer.
Now, Lucy doesnt even recognize him anymore.
Crowley: Hes the devil.
Rowena: You say that like its a bad thing.
Yes, thats his mother.
(In this moment, it hit me that weve hardly ever watched the guys vomit on this show.
And Im not complaining.)
Apparently, smiting sickness is a thing created by all of the energy released.
when Crowley informs him that his brother is in hell…with Lucifer.
And yes, we get to relive Cas yelling Hey, assbutt, because this show loves us.
And no, Lucifer still doesnt get that reference.
He had balls back then…and now hes gone soft.
And that leads us to the final stop on the Sam tour.
The house Sam shared with Amelia after Dean was sent to purgatory.
Lucifer then calls Sam out on letting Dean talk him out of closing the gates of hell.
So if Sams not strong enough, Lucifer-Sam can be.
After all, Snapping necks and cashing checks is what I do.
(How have we gone so long without Lucifer?)
Jumping back to the woods, Castiel runs into a number cruncher of an angel named Ambriel I think?
sent by heaven to see if Amaras still alive.
You help, but Sam and Dean Winchester are the real heroes.
Have you seen every episode??
And its a good thing, too, because Amara consumes her real fast.
Spoiler: Shes right.
Instead, Amara gets to be the second woman to judge Castiel this episode.
She claims he smells of fear and self-loathing.
But she doesnt kill him.
Instead, she gives him a job.
But for now, she hands him a fancy box and sends him to hell.
Also, a special shout-out to this interaction:
Crowley: Dont worry about Sam.
Dean: Im sorry, have you met me?
Back inside, Crowley uses tea to weaken Rowena while Dean puts the witch catcher on like a collar.
As Lucifer puts it, Michaels probably sitting in a corner singing showtunes and touching himself.
So for those of you whove been dying to know what happened to Michael, theres an image youllneverforget.
All of this is to say that Lucifer is the only option when it comes to defeating the Darkness.
But Sams closing argument is equally as convincing: No.
Whoever wins, everyone else losses, Sam says of Lucifer and the Darkness.
For him, this about having faith in his friends and in his family.
As he says, We will find a way.
#boom
The bad news?
Lucifers plan B is torture.
But thankfully, when Amara zapped Cas, she sent him to Billie, who gets him into hell.
First up, Dean and Cas needs to save Sam long enough for Rowena to complete her spell.
And that means were getting a cage fight, yall!
Lucifer cues up Heaven Must Be Missing an Angel, and then the fighting begins.
(Can someone kindly get me a GIF of Lucifers dance moves?)
But somethings not right.
In fact, nobodys had a great day (other than us viewers).
Back in hell, Crowley takes advantage of the witch catcher and asks his mother why she hates him.
Sorry if you were enjoying that moment because Castiel has just returned to hell…except ITS NOT CAS.
So LUCIFER IS IN CASTIELS BODY.
I guess, technically, hes in Jimmys body?
Whatever, you get it.
And when she says yes, he snaps her neck.
The lesson: Dont be a groupie.