So she dances. A different dance than the last one, or at least not quite the same - despite their circumstances, this one is happy, almost joyful, communicating a sort of relentless optimism. 

"Your light is lovely," says Tutu. "But why are you shutting people away in the darkness?"

"All I want is to shine for someone, to bathe them in warm and tender light. But the people who were precious to me - they've forgotten about me. I suppose they never needed me at all. But you do, now, so I can shine for you forever."

"Um," says Serafin. "Is there like... food down here. Because if not, this isn't going to be much of a forever."

"Yes. You can't keep people locked up forever. I'm sure that many people would be glad to dance in your warm light; you don't need to force your warmth on anyone. That will only bring them pain."

The lamp spirit comes down from the ceiling and decides to go back to hugging Serafin.

"I'm sorry," she says. "I didn't mean to hurt anyone."

Awwwwww. He hugs the lamp. She's a very huggable lamp.

"I'm fine, see? It'll be okay. The magical ballet princess is good at this."

Hugs!

"Will you stay with me, if we go upstairs?"

"Of course. I promise."

"OK," says the lamp spirit, softly. 

"There was someone else here," says Princess Tutu.

The lamp girl nods, motioning to a set of boxes where Mytho is sleeping, curled up around an ordinary oil lamp. "I thought he might be cold."

"That was thoughtful," says Princess Tutu. "Will you return the shard of his heart?"

"Yes," says the lamp girl. "If you promise not to forget."

"I'm not gonna forget you," says Serafin, hugging her some more. "You're the most huggable lamp I ever met."

The lamp girl smiles, reassured, and returns to the lamp. 

Tutu draws another heart shard out of the lamp. "I am the feeling of affection, shattered and forgotten," it informs her, before returning to Mytho. 

Mytho blinks sleepily and wakes up. "Tutu?"

"You should hurry," she tells him. "Someone is waiting for you."

...Serafin looks at the lamp, and looks all around at the room, and looks at the lamp again.

"Where'd she... go?" he asks hesitantly. "Was she just - magic stuff, like the forest fire - did we just kill the lamp girl by accident—"

Princess Tutu regards the lamp with some concern.

"I don't know," she says. She picks the lamp up carefully and hands it to Serafin. "But you should watch after her until we know more."

He hugs the lamp, also carefully, and nods.

"You're a good lamp," he says, to the lamp. "You're pretty and warm and bright. I'm sorry if we killed you."

She nods solemnly at the two of them, and then they make their way out of the tunnels.

Serafin holds his new lamp very carefully and gently. She is such a good lamp. He might be crying a little about this lamp. Hopefully no one will mention it.

Nobody mentions it. It mostly doesn't occur to Tutu or to Mytho that this is the sort of thing that someone might be inclined to mention. Mytho heads off to the Fire Festival once they've exited the catacombs.

"Thank you, Serafin. Goodbye for now," says Princess Tutu.

"Bye, magical ballet princess."

She dances off.

When she's back to being a girl, she wanders off to the Fire Festival to see whether Mytho got to dance with Rue. (He did. Not in time for the festival proper, they missed that, but they're dancing together as people clear out of the square.) They seem happy together.

And that's how it should be.

Serafin takes his lamp home and puts her in his room and pats her lampshade and apologizes again for possibly having been an accessory to her accidental murder.

The next morning he goes early to class, brings the lamp, and sets her up in a corner of the room where she'll have a nice view.

That's good! Or like, better than it could be. She couldn't have just left Mytho without the ability to feel affection for anyone, that'd be horrible, but she does really wonder about the moral implications of turning the lamp back into a normal lamp that apparently comes without a magic lamp spirit.

They have a combined class today. Duck doesn't go out of her way to talk to Serafin, because what if he asks about Tutu again (or worse, it's like when she danced with Giselle and he thinks she just ran off and abandoned him), but she does stop and chat with the lamp for a bit, because maybe it can still hear her. And she'd feel bad if she were a duck forever and then people stopped paying attention to her.

Serafin smiles at her when he sees her talking to the lamp. He does not ask her any questions about magical ballet princesses.

Oh good! She waves awkwardly and will just go sit with the rest of the beginner class.

Mr. Cat informs them that they have all been given special permission to sit in on the dress rehearsal of a traveling ballet troupe that has just entered Gold Crown Town. He expects everyone to be on their best behavior. All of the students are pretty excited about it; the Eleki troupe is supposed to be really good.

Sounds like fun! Serafin will bring his lamp.