Supernatural season 10 spoilers "Supernatural" will return with more dark drama when Season 10 premieres on Tuesday, Oct. 7, at 9 p.m. EDT. Photo: Jack Rowand/The CW

Can you believe that the “Supernatural” Season 9 finale is already here? It feels like just yesterday we were watching Sam Winchester greet death with open arms when episode 1 of the ninth season aired. Now, 23 episodes later, a lot has changed -- and you’ll be able to witness the evolution of the Winchester brothers and their tumultuous relationship when the final episode of Season 9 airs on Tuesday, May 20, at 9 p.m. EDT.

Check Out The 7 Most Shocking Moments From The Season 9 Finale Here!

According to the synopsis of “Do You Believe in Miracles,” you can expect “Dean (Jensen Ackles) to feel the effect of the First Blade, and Metatron (guest star Curtis Armstrong) to make his move against humanity. Meanwhile, Sam (Jared Padalecki), Dean and Castiel (Misha Collins) will face shocking consequences when taking the fight to Metatron.”

Sounds intense, right? Well, according to Padalecki, you have no idea just how extreme Jeremy Carver got while writing the season finale. In fact, we’ve decided to break down everything we know about episode 23 to help fans prepare for the anticipated finale. Ready?

1. Tune in until the very end: “The last five minutes of the finale are the more important five minutes in ‘Supernatural’ history,” Padalecki confessed to “Something happens that has never happened before in the show. We’ve gone left, right, up, down, done all sorts of things in the show, but we do something in the finale that we’ve never seen.”

Hmm, what could he be talking about? Perhaps it has something to do with Dean’s altered personality due to the First Blade.

Supernatural season 9 spoilers The Season 9 finale of "Supernatural" hints that Dean will get darker than ever before in episode 23. Photo: Jack Rowand/The CW

2. Dean gets dark: Sam’s big bro has been struggling immensely with the dark side since he got his paws on Cain’s weapon. And according to Padalecki, his TV bro will submerge himself fully in darkness during the Season 9 finale.

“We're going to see him go all the way," Padalecki admitted. "There's a parallel with Dean in Season 9 kind of going through what Sam went through in Season 4, where he feels empowered, he feels strong, he feels like he's doing the right thing. And obviously it can take over."

Supernatural season 9 spoilers Sam and Castiel will pair up in the Season 9 finale of "Supernatural" to try and save Dean from darkness. Photo: Cate Cameron/The CW

3. Samstiel: Dean fans shouldn’t fret too much because reports indicate that Sam and Castiel will step in to bring their brother and friend back into the light.

“Sam and Cas are going to have to team up because Dean has powers that are heretofore unknown, so they’re surprising both Sam and Cas,” the actor told TVline. “We have to go to a pretty big extreme to take care of what’s going on with Dean.”

4. Craving Castiel scoop?: According to Collins himself, his character may have to go to great lengths to save his own skin now that he lost all of his angelic powers. “I’m interested to see what the writers do with Cas’ fading grace in Season 10,” he confessed.

Supernatural What will happen when "Supernatural" returns with Season 10 on Monday, October 7? Photo: Cate Cameron/The CW

5. Brotherly love: This season has been rough for fans as we watched Sam and Dean’s relationship evolve from a loving one into a dictatorship. However, all of that will change come the season finale.

"We see it in a strange situation, but we do see Dean understand that it's not a dictatorship, it's a partnership," Padalecki revealed. "I think Dean will see that Sam loves his brother. Dean will certainly see that Sam is there for him and know Sam's commitment.”

6. Who will survive and who will die?: We’ve been wondering this inquiry ourselves. But never fear “Supernatural” fans! Your favorite trio will be returning next year fully intact. Collins has signed for Season 10 as a series regular while Padalecki and Ackles have already announced what their roles for the upcoming season look like. HINT: Think strong brother-bonds.

Supernatural The cliffhanger of the "Supernatural" season 9 finale will leave you craving for more. Photo: Cate Cameron/The CW

7. Cliffhanger galore: That’s right, prepare to be on your toes until the very last second, “Supernatural” fans. This chilling finale will torture your soul all summer long until Season 10 premieres to answer one of the most jaw-dropping moments in SPN history.

“More than any other season before, this season finale has implications for Season 10,” Padalecki said, adding that it will change the landscape “big time.” “It may be the best last 10 seconds of a season that we’ve had in five years,” Collins added. Now that’s what we’re talking about!

8. Should we buy tissues?: The Season 9 finale of “Supernatural” will be so emotional that even the toughest, fiercest grown-men will end up shedding a tear or two. “Parts of it made me laugh, parts of it brought me to tears and parts of it really gave me that feeling where I was excited to see what happens next,” Padalecki said.

Do you think you’re ready for the Season 10 finale of “Supernatural”? Chime in with your predictions for what will happen when the hit CW series airs its episode 23 tonight.