At Donghae's mansion, he was talking to Sulli's shadow...

Donghae: Tonight, you will go back to the shadows world

Sulli's Shadow: W-What?! Please don't! I don't want to go back there! *kneels down* Please don't throw me away

Donghae: I just need you to do one last thing *whispers to her ear*

Inside the shadow's world, Sulli was only able to hear that he was going to free her that night...

Sulli: Did you hear that? I will go back

Taemin: That's good

Sulli: *looks at his arm* What happened to you?

Taemin: *hides it behind his back* It's nothing

Sulli: *grabs his arm* It's getting black!! What happened?

Taemin: I...*sigh* Look, since I have been trapped here for so long that we might be changing places

Sulli: What do you mean?

Taemin: I'm becoming the shadow

Sulli: *shocked* No, that can't happen, I won't let it happen, I'll force Donghae to let you go--

Taemin: Sulli! It's too late, once it starts it doesn't stop...

Sulli: *tearing* That can't be...I...Is there a solution?

Taemin: I'm sorry but there isn't...

Sulli: *crying* I can't... I can't let you disappear!

Taemin: *hugs her* I also don't want to let you go, I can imagine that my shadow felt like this too...I love you

Then the ball started, the room was full of vampires wearing masks, everyone was dancing, then Minho arrived with the others...

Minho: Is everyone ready?

Everyone: Yes

As soon as they entered, Donghae was putting his mask until Jessica saw them...

Jessica: My lord, everything is going as planned

Donghae: Go and check on Sulli and Sunny

...

Jessica: Are you ready?

Sunny: She's ready but she keeps looking outside the window

Jessica: *angry* Sulli! Sulli! Sulli Baskerville! Shadow!

Sulli's Shadow: *looks at her* What?

Jessica: It's time

They went downstairs, they introduced her as Donghae's daughter, she went towards him and then...

Donghae: Now, my beloved daughter will sing us a song

Tiffany: *annoyed*Aish, how dare he claims her as his daughter, I will--

Eunhyuk:*holds her closer to him* Tiffany, calm down, it's not time yet

Tiffany: *blushes* Alright...

(listen to this song: http://www.youtube.com/watch?v=dMFYEkbCTck)

Minho: I had never heard her sing

Krystal: She has a pretty voice

After her performance ended everyone started dancing and suddenly everyone started changing their partners, Minho was hoping to get to dance with her, when he finally got to dance with her, he wispered to her ear...

Minho: I'll meet you later, go with Krystal.

She didn't answered and walked away, then she met Krystal...

Krystal: Come with me

Sulli: *nods*

They walked outside the mansion, Krystal took her to where Minho was waiting for her...

Before they finally arrived there, Krystal noticed that Sulli wasn't fully herself...

Krystal: Sulli-ah, why haven't you told me anything up until now?

Sulli's Shadow: Just because

Krystal: *stops Sulli* You're not Sulli

Sulli's Shadow: *eye color changes to red* Do you think so?

Krystal: *scared* W-What?

Sulli's Shadow: *grabs her by the collar* Get lost *throws her away*