After their encounter with Orochimaru, Team RWBY carried the injured Sasuke back to Beacon. As Zwei guided them back to Beacon, Sasuke's condition worsened. 

Ruby: Hang on, Sasuke! We're almost there! 

Soon enough, they reached Beacon Academy. They were immediately approached by Ozpin. 

Ruby: Professor Ozpin! Professor Ozpin! We...we need help! We...we....

Ozpin: Wait, Ruby. Take a breath. Collect your thoughts.

Ruby took a moment to catch her breath. Once she does so, she speaks. 

Ruby: We...we were trying to find that woman and we....we were attacked by this....snake guy! Sasuke managed to beat him, but....but he...he...that snake guy did something to Sasuke! 

As Ruby said this, Ozpin looked at Sasuke. The first thing he saw was the symbol on his neck. Upon seeing this, a visible look of shock was seen on Ozpin's face. 

Ozpin: Orochimaru....

Yang: Y...yeah! Orochimaru! He called himself Orochimaru!

Blake: You...you know him? 

Ozpin: Unfortunately yes. Orochimaru is a very dangerous man. You are all lucky to be alive. 

Weiss: S...Sasuke! Is he...

Ozpin: I will tend to Mr. Uchiha. 

With that, Ozpin takes the wounded Sasuke to a medical facility in Beacon. Once Ozpin sets Sasuke on the medical bed, he looks at the mark on Sasuke's neck. 

Ozpin: The Curse Mark.....what twisted game are you playing at, Orochimaru? 

Suddenly, Sasuke begins screaming as the pain intensifies. Wasting no time, Ozpin places the hilt of his Long Memory cane on Sasuke's neck. The cane then begins glowing with magic. The magic then forms a seal around the Curse Mark. Sasuke once more screams in agonizing pain before passing out. Ozpin takes a deep breath as a seal begins forming around the Curse Mark. 

Ozpin: That...should suppress the Curse Mark for the time being. 

???: To think that you've become strong enough to seal away my Curse Marks. Your skills never cease to amaze me, Ozpin. 

Ozpin turned around to see Orochimaru in the room. Immediately, Ozpin prepares the Long Memory. 

Ozpin: Orochimaru.....

Orochimaru: As much as I would love to reminisce about the past, I didn't come to see you. 

Ozpin; What do you want with Sasuke Uchiha?

Orochimaru: The power of the Uchiha bloodline is a wonder to behold. Once upon a time, an Uchiha was more powerful than all the Maidens. Even the legendary Silver Eyes cannot hold a candle to the Uchiha's power. It is only natural that I would desire such power. It is a shame that the Uchiha Bloodline is all but extinct. 

As Orochimaru began approaching Ozpin, the Beacon Headmaster pointed the Long Memory at Orochimaru.

Ozpin: Don't come any closer, Orochimaru! Take on more step towards Sasuke and one of us will die!

As magic begins building up in the Long Memory, Orochimaru stops before chuckling. 

Ozpin: Funny, is it?

Orochimaru: Poor old Ozpin. All your noble efforts....all in vain. Do you really believe that the spell you placed on Sasuke will hold? Do you think you can keep him from what he truly desires? You know I'm right. A heart like his that only hungers for one thing will not be denied no matter what obstacles you put in his path. He is an avenger, isn't he? 

Ozpin: You think you can take advantage of that? Not Sasuke. Not while I still draw breath!

Orochimaru: You cannot stop it. At some point, Sasuke will come to me of his own free will in search for power. Unless you carry out your threat to kill me. Now is your chance, Ozpin. Take it if you dare. But should you die, nothing will stop me from taking Sasuke myself. And we both know that the time it takes for your....condition to manifest into another. And with Salem's agents so close to Beacon, do you really think you can afford to leave the bastion of your power without it's ruler? 

Ozpin pauses as he laments on Orochimaru's words. Orochimaru once more laughs. 

Orochimaru: I get no pleasure when the world is still. It's....like a windmill that isn't turning. How boring. So I've decided to put things in motion myself. 

Ozpin: Whatever sick and twisted game you're playing, it won't work. We'll stop you. 

Orochimaru: It's ironic, isn't it. You have the knowledge of countless lifetimes at your disposal, yet you are not one step closer to stopping Salem. While her power grows, yours wanes. Do you closest of followers know the truth about the war you've asked them to fight or have you kept the truth from them?

Ozpin fell silent as Orochimaru began walking away. Ozpin kept his eyes on Orochimaru, not once lowering his guard. Before he left, Orochimaru turned to face Ozpin. 

Orochimaru: I'll be seeing you soon, Ozpin. 

With that, Orochimaru left. When Orochimaru was gone, Ozpin took a deep breath before checking on Sasuke. He inspected the seal of the Curse Mark. The words Orochimaru spoke echoed in Ozpin's head. 

Orochimaru(Past): Do you really believe that the spell you placed on Sasuke will hold? Do you think you can keep him from what he truly desires? You know I'm right. A heart like his that only hungers for one thing will not be denied no matter what obstacles you put in his path. He is an avenger, isn't he?

Ozpin: Damn you, Orochimaru.....damn you....

With that, Ozpin arranged to have Sasuke monitored until he recovered. In that moment, Orochimaru had revealed himself to Ozpin. For now, the Curse Mark had been sealed. But Ozpin what Ozpin couldn't foresee was that the power of the Curse Mark had already taken it's hold on Sasuke.