After Fredrick stepped through the portal, Pitch wrapped the imaginary chain around his hand and gave it a tug. He flowed a nightmare through it, giving whoever's it was a small fright.

Pitch steppe out of the clinic, "Youchi is it? You do know it's against school rules to perform magic on teachers. There are severe punishments towards that thing. Fortunately, it's in both our best interests that no one knows what I'm doing in the clinic. So how about we make a deal? If you do me one favor, I won't report this to Gothel."

XXX

"Too long." Jack said calmly, "long enough. To watch my skin fall off."

Jack looked at his hands, slowly, but surely, his body was disintegrating into black dust. Within time, his entire mass would disappear.

"I saved Anna's life. As long as she stays in that ice block, the curse won't spread..."

Cursing could be heard from inside the cave. It was probably Elsa shouting again.

Jack took a deep breathe, "something Pitch didn't tell you is that the people who have been fully transformed will die if the source is destroyed. You can kill the worm and save those patients, but it'll kill me and Elsa in the process."

Jack stood up from where he was sitting. He waved his staff and created a few demonic snowmen. "I hope you understand why I have to do this." 

The snow minions charge and Fredrick.

XXX

Elsa sent some ice monsters through the hole, "that ought to teach those brats..."