He's standing on the bridge, wondering what to do. He considers what would be worse, breaking Starfleet's Prime Directive or a life without Spock. The answer is easy enough.
"He'd let you die." Bones says and a part of Jim knows this could be true. They're very different, Spock is all about regulations and logic while Jim is all about instincts and heart, but Spock is also his friend. Somehow Jim has gotten to the point where that's all that matters.
So Jim orders the Enterprise into a volcano to save him and makes sure his whole Enterprise family is unscathed. He won't bore Starfleet Command with the details.
His clothes are stained with Spock's green blood, a physical reminder of the fact that Spock is so foreign from him it shouldn't even be possible for them to coexist. He stares at his hands, the same hands that stopped that blood from overflowing and killing his best friend and then shifts his gaze to Spock's still form.
Bones says it's a healing trance and that Spock will make a full recovery. Jim can't get over the fact that Spock hurt himself to protect him, his heart clenches when his mind goes back to that terrible day and he sees Spock's tears on the other side of a glass again. Despite all his pain he had felt warmth and awe at realizing that Spock could control himself and accept his own death but not Jim's.
As he watches his friend rest that amazement comes back full force to hit him. This is what the older Spock had talked about and a shiver courses through Jim as he realizes they almost didn't have this. What if Nero had succeeded? What if he hadn't taken Pike up on his dare? What if a million things had gone differently and they had never met?
He's overwhelmed with gratefulness that for all they've suffered, this wasn't taken from them. Despite everything they still have each other.
"Jim." That was the first time Spock had called him by his first name, on the Jellyfish during the whole Narada crisis, setting the annoying trend of only calling him that when one or both of them were about to die.
Jim hadn't let him finish, "It'll work, Spock."
He knows now that Spock didn't believe him back then, but that changed over time. Now when Jim says things like "Trust me" or "I have a plan" Spock just nods and dives head first with him, because they both know they're better as a team. It's the kind of faith that defies logic and it hits him every time.
Every time they only need one look to understand each other. Every time they're the first person they turn too. Every time Spock is the one who initiates a kiss and it takes Jim's breath away, because he can't believe they had to cross the universe to find this kind of happiness and perfect understanding in someone so alien.
Jim used to hate the stars because they took away so much from him, he used to hate them for the longing he felt when watching them shine in the night sky.
Now he knows they were calling him to his destiny.