Ingrid was in the ice cave.
"It's okay. Come. Be my sisters." Ingrid said.
"I can't do it, Anna. I can't hurt her." Elsa said.
"Yeah, well, I can." Anna said.
"Wait! Stop!" Jack ran in.
"Jack! No, she's too dangerous." Elsa cried.
"You should listen to my sister and go." Ingrid said.
"Your sister? She's your niece. And whatever you're gonna do? Well... Don't. Elsa, I found this on the beach. It's from your mother. She must've thrown it into the ocean before their ship sank." Jack said.
"Oh, just be careful." Elsa said.
"No, I'm not gonna be careful. She needs to hear this. You all do." Jack said.
"Elsa, Anna, I don't know if your father and I will ever get back to you, but I need you to know we were wrong to tell Elsa to conceal her powers." Gerta's voice said.
"Yes. Her last words." Ingrid said.
"I feel terrible that it happened before and I can't let it happen again." Gerta's voice continued.
"What?" Ingrid said softly.
"My sister Ingrid, like you, also had ice powers. I never told you about her or my other sister Helga, but I should have. They were beautiful and kind and wonderful, and I was fearful. And I let that fear guide me. I let Ingrid hide when I should have celebrated her for the person she was. I loved her so much." Gerta's voice continued.
"You're lying! My sister hated me! She called me a monster! She put me in that urn!" Ingrid said.
"In this crystal are the memories of my sisters, which I stole from the people of Arendelle. Please return them. My sisters deserve to be known. In a cave in the north valley, you'll find an urn that contains Ingrid. Please do what I should have done long ago and release her. When you see her, please tell her I love her and I'm sorry. I'd give anything to take back what I did, to hold her hands one more time." Gerta's voice continued.
Ingrid started strangling Jack with her powers.
"Ingrid!" Elsa said.
"Let him go!" Anna said.
"I understand, Ingrid. I understand now why you cast this curse. But you can come back from it." Jack said. "Pitch tricked you. But you can stop this."
"Understand me? How could you? You're nothing like me! You understand nothing!" Ingrid screamed.
"You're right. I'm not like you." Jack said. "But you're a part of our family no matter what. And family never gives up on each other. We can't let fear win. We can't let Pitch win."
"You lie!" Ingrid slapped Jack. She took the letters and read them. "Oh. Oh, Gerda. Oh. What have I done? I need to reverse this."
"You can't. The only way is if you..." Jack said.
"I know. I have to destroy myself." Ingrid said.
"No, Ingrid. Wait!" Elsa said.
"There's no other way. I am a monster, not because of my powers, but because of what I let them turn me into. I have to undo this." Ingrid said.
"No, Ingrid. You'll die." Anna said.
"I know. It's okay. Elsa, Anna, you found each other. You... You deserve your memories. You three are so special. Never forget that. Oh!" Ingrid said as the magic started to tear her apart.
"There has to be another way. You deserve your happy ending, too." Jack said.
"Long ago, a prophecy told me that you would lead me to just that, Jack Frost. And this is it. All I wanted was to have my sister's love, and... Now I have it. Now... I get to join them." Ingrid said.
The magic swirled around and ripped Ingrid apart.
"She sacrificed herself for us, for all of us." Jack said.
"Anna." Elsa said.
"Elsa." Anna said.
"We must follow through on our mother's last wish. We must bring back the memory of Ingrid and Helga to the people of Arendelle." Elsa said.
"We will." Anna said.
