Chapter 68.
After his shower, Cas returned to the kitchen and found Jack there, eating his breakfast. Dean was at the sink and said, "Okay, I'm gonna leave you two for now. I'll be in the library with Sam, if you need either of us."
"Thanks for the food." said Jack.
"You're welcome." said Dean. He left rapidly.
"What's going on?" said Jack.
Cas raised a warning hand until he was sure Dean was out of earshot. Then he said, "Would you like to tell me what you're working on?"
"Working on?"
"You were studying something last night."
"Everything, really. I need to understand the universe."
"And the Empty?"
Jack shrugged. "It's part of the universe."
"It's a vital part and if it goes, the whole universe will collapse around it."
"Do you know that, or just fear it?" said Jack, "Because, honestly, I don't think my grandfather has things in that tight of a system. I think there's a lot of slack and some redundancy."
"You're talking about the fabric of reality." said Cas, "You start pulling threads, we don't know what could unravel."
"Exactly. We don't know. So we need to find out."
"By doing it?"
"No, by reading every word ever written on all of it, by asking anyone who knows anything about it. If I have a cosmic destiny, shouldn't I understand how the cosmos works?"
"And that's your intention, to fulfil your destiny and not to overturn my deal?"
"Maybe I can do both."
"What I did, I did for good reasons." said Cas.
"Yes."
"And for the same reasons, I have to ask you never to try to undo what I did."
"No."
"No, you won't try to undo it or no you won't promise not to?" said Cas.
"If I'd made that deal for you, would you stand back and let me go?"
"That question is meaningless. My whole purpose is to keep you alive."
"Mine is to protect and serve you."
"Yours is to save the world." said Cas.
"This world needs you."
"Not even this bunker needs me."
"How can you say that?" said Jack.
"I'm not here because I'm useful or powerful or wise. I can't fight Michael. I can't protect anyone from him. I have no brilliant strategy or any prospect of making one. I am here because the Winchesters pity me."
"That's not what they said at supper last night." said Jack.
"Well, they're not going to come out and say it, are they? That would be cruel and cruelty is not in their natures. But I see it in their eyes. I hear it behind their words."
"No, you don't. You imagine it, because it fits with how you feel about yourself. Do you think that I pity you?"
Cas had never considered that. He didn't want to. All love felt like pity to him sometimes.
"You do." said Jack, looking as if he had just been slapped.
"No." said Cas. He could not let his feelings lead him to hurt Jack. Jack was innocent. Maybe he imagined the pity of others, maybe he didn't, but he was not imagining the pain in Jack's eyes.
"Do you think I don't love you?" said Jack.
"No. Jack, if I thought that, I wouldn't be here at all."
"Because, if there is any doubt, I can tell you that there is no-one, in this world or any other, that I love more."
"What about your mother?"
"As much, not more." said Jack.
"You don't know all my mistakes, the terrible things I've done."
"I don't care. I know the good you've done. I know what you've done for me. You want me to promise not to try to save you? Well, I could promise that, hand on my heart, but in forcing me to make that promise, you'd be forcing me to break it, to break a promise to you. Please don't do that."
"What I did was done to protect you. If you undo it, you could be taken."
"Better me than you."
"Jack, I'm nothing. Leaving aside all sentiment and all argument, you are a nephilim and I am just an angel."
"You are Castiel and I'm only Jack." said Jack.
"If you die, everything I have done in my life is meaningless. I die with you. If you fail, because you stopped to save me ... "
"If you die because I didn't, everything else is destroyed."
"Angels are disposable. We are designed to be."
"Not this angel, not to me, or to Dean and Sam. I could get them in here. We could ask them."
"We can't do that. You promised not to tell them."
"And I won't, unless you force me to by refusing to let me help you escape from you know where. I'm immortal, Castiel. That's an awfully long time to be mourning you."
"Don't mourn me. I'll be at peace." said Cas. He hated lying to Jack, but could think of no alternative.
"I won't be." said Jack.
"To save you, I gave up my life, my love and my link with Sam and Dean. A high price, but worth paying, unless you die anyway." said Cas.
"What if I could find a way to save you at no risk to myself or the universe? I mean, you're not set on dying, are you?"
"I don't want to die." said Cas.
"Good. So, that's agreed."
"But only if there is no possible risk to you and no possible harm to the world." said Cas.
"That promise, I can make and keep." said Jack.
"Thankyou." said Cas. It felt like a victory. "And be careful what Dean sees you researching. He's clever. He'll work it out." he said.
"I'm not trying to let them know, but it's hard to keep this secret. I wish you'd just tell them. Then we could all work on it together."
"You don't think Michael is enough for them to deal with?"
"I think Michael is an excuse for you not to tell them. I think, if Michael didn't exist, you'd still keep this from them."
"I wish you didn't know. I wish you didn't have to keep this or any secret. I'm truly sorry. I don't blame you for being angry."
"You really have trouble understanding emotion. Their love is pity to you and mine is anger." said Jack, "Maybe you should consider the possibility that you're wrong about other things, like that you have to accept your fate."
"Not my fate, my choice." said Cas.
"If you chose, you can choose again, with the Empty and with Jules." said Jack.
"You're very young." said Cas.
"Yes, I am. It doesn't necessarily make me wrong."