At the moment Spock recognizes Jim Kirk young and strong in front of him, an emotion that runs deeper than the pain that wracks him swells steadying and calm beneath his Vulcan veneer of unshaken control. His last memories of Kirk are of an older man, time and a life well lived adding laugh lines to his face, weight to his frame, and strands of grey to his hair. His last memories are of Kirk's sudden death tearing a ragged hole in his life. Yet, here in a past that's not Spock's own, Kirk is alive.
While the agony of Vulcan's collapse and his own terrible culpability continue to storm inside him with all a Vulcan's dangerous passion, that Kirk stands here and now with a chance to live anew fills Spock with an uncanny hope. Kirk's vitality is the promise that he can survive this, even now, so near the natural end of a life he'd begun to fear had stretched too long and too thin.
Now, he learns suddenly that more is wrong in the world he's wrought than the destruction of the world where his human mother gave birth. The young man he's become in this shattered series of events separated himself from Kirk forcefully and dangerously. The young man he's become is wracked with the same pain that tears at the heart of him, but possesses little of the practiced control and long experience that allows him, in his age, to see to the other side of it.
Kirk's mind is achingly familiar and shockingly foreign beneath his touch. He gives of himself with the trust of years of friendship, certain that this stranded and desperate young Kirk is still capable of all the greatness he's achieved before.
Kirk reels with the deep and powerful sorrow that washes through his mind, jump-starting his heart pounding as furiously as during his frantic escape across the ice. This is no human sadness, this alien mourning that floods the deepest reaches of his consciousness with the pain of loss and tragedy. It's when he catches his breath from the unexpected surge of staggering Vulcan emotion, and while Spock fills his mind with images of a recent and terrible past, that he recognizes all that keeps Spock's alien passion from eclipsing his ability to remain conscious.
Faith. Love. Certainty. As surely as Spock draws strength from his presence, Kirk is strengthened by the absolute trust and affection that radiates from the stranger who's so overwhelmed his waking mind.
Kirk flickers through memories of a childhood spent scraping by, stealing scraps of dignity and starving from loneliness. Even Pike's invitation grated him as charity. Never before has anyone thought as much of him as this man he's never met. No—this man he's met, a peer who in the world he knows has nothing but disdain for him. Even as Spock lays the burden of knowledge and the ability to act on that knowledge squarely on Kirk's shoulders, Kirk experiences for the first time the love and absolute trust of another.
It shakes him to his foundations. Through all the daring and bravado and the times he's risked his life to prove to himself that he's alive, has he ever once seen himself as capable of the heroism his father achieved? All his life it seems like he's been shouting at the world at the top of his lungs, defying every obstacle placed in his path with a rebellious determination to scrape through on only his own stubborn disregard for convention.
This man, old and alone and in pain in ways Kirk has never imagined, radiates a belief in him and the good of him that's wholly inexplicable. Spock leaves him shell-shocked with his cheeks wet from tears. So many of them are from Spock's sorrow, and the rest are for the life he's wasted drunk and the relief of finally tasting the intimacy he's never found tangled in the sheets one meaningless tumble after another.
Spock is left startled by the memories that Kirk leaves behind in his mind. He longs suddenly to quietly bring him into his embrace as he would have had they been in private years ago in a world that's irrevocably lost. A part of him dutifully preserves the memories of Kirk's touch and intimacy as the best years of his long life, taking solace in the knowledge of Kirk's love no matter how the decades pass.
He knows with immediacy that he cannot have what's been lost to him for longer than he cares to remember. He's strong with the wisdom of years and in firm control of all the emotion within him, as wild as it churns, today. But somewhere in this vast universe, and not too far to catch, he's a firestorm of pain without the trials that have tempered him or the surety of his devotion to James Tiberius Kirk to steel him.
He needs Kirk, he's learned that beyond any doubt, and has no idea what a disaster may come to the Federation if Kirk isn't at his side. And, so, setting selfishness away, he resolves to bring Jim to his side and lose him, once more, at the same time.