You should be here, Jim thinks as he sits against the wall of the warp core chamber. He can feel the radiation running its course through his body, taking his life force, and knows that he doesn't have long. He sees the grim look on Scotty's face as he speaks to someone—probably Spock—through his communicator.
He finds his prediction to be correct when his First Officer appears before the older man. He points him toward the chamber, and Spock runs to him. He can briefly hear Scotty telling him something about radiation contaminating the whole compartment if he opens the door.
Jim moves around in an attempt to make himself as comfortable as possible. He reaches up to close the warp core chamber door that sits behind him. His breaths become harder, shorter. He looks at Spock through lidded eyes.
"How's the ship?" Of course that's the first thing he asks. After all, he's practically married to her.
"Out of danger." Jim feels relief flood through him.
"Good."
"You saved the crew," Spock says.
"You used what he wanted against him…that's a nice move."
He's surprised at the emotion that's evident on Spock's face.
"It is what you would have done."
"This…this is what you would have done. It was only logical." Everything hurts, and he's struggling to breathe. "I'm scared, Spock." He's shocked at the revelation. He's never been one to admit fear. "Help me not be."
Even though he's speaking to Spock, he's thinking about his father, too. Is this how he felt when his end was drawing near? Spock is there, and Scotty's not too far behind. He's grateful for them; they're part of the family he found all on his own. But as he enters into his final moments, it's not just his crew he wants there. He wants his father to be on the other side of the glass. He wants to hear his father tell him that everything's going to be okay, that he's so, so proud of Jim, and that he loves him more than anything in this world or the next. Jim focuses back on his First Officer, his brother.
"How do you choose not to feel?"
Spock shakes his head, and Jim sees tears sparkling in his eyes. Jim can feel some begin to form in his own. "I do not know," Spock replies. "Right now I am failing."
Both are silent for several moments. Jim finally breaks the silence. "I want you to know why I couldn't let you die…why I went back for you."
Spock's response surprises him."Because you are my friend."
He feels himself slipping, and finds his thoughts go back to her dad. All the time he's spent hating his father, he now regrets. He finally understands why he had done what he had. Love. Love for his ship. Love for his crew. Love for his family. He hadn't even met Jim, but he'd loved him so much that he'd given his life to save him. Love had motivated him just as love had motivated Jim.
He's hated how people had always compared him to his father, but in this moment, he wouldn't want to be compared to anyone else. Jim and George had a lot more in common than just genes, and he'd never been more proud to be the son of a hero. He'd spent all that time hating his father, but now he truly understands the sacrifices made and loves him more than he ever thought he could.
With the last bit of strength Jim has left, he lifts his hand and places it on the glass. Spock follows suit. He does his best to form the Vulcan farewell salute, Spock's fingers moving to match his. They share one last glance.
He can't breathe, can't speak. He hopes this final look conveys what he feels for Spock. For Scotty. For Bones. For Uhura and Chekov and Sulu. For the rest of his crew, his ship, and his mom. Everything darkens and his body begins to numb.
He has one last wish as he took his final breaths. He wishes to meet his father, to have him be the first thing he sees when he opens his eyes again on the other side.