13X21 spoilers! Big ones! Last warning.
He can’t tell how he knows where to go, but somehow he does. It’s like Sam Winchester’s DNA is linked to his -- well, to his vessel’s -- more than that of his own son, as aggravating as that may be (they took Jack from him, and he could hear them think about the boy when he was in the bunker, how they worry about him love him hope for him. His son. His). After all those years down below, he can find Sam wherever he goes. Before, it was a challenge. Not after the Cage, though. Not for one moment since the Cage.
Sam leaves traces of terror behind like a trail of fresh blood in the snow ever since then, always discoverable. Lucifer finds that it’s no different here, another dimension or no. In a world that’s desaturated of color and vast in its emptiness, the trail glows as bright as stolen grace. He likes to think that Sam can feel it, too. Can sense him honing in, getting closer. Hunting him. Nice little symmetry.
When he finds him, though, Sam isn’t capable of shuddering at his resourcefulness. Sam is gone. He is lying on the ground in one of the darker parts of the foul-smelling tunnel (cave, really), a broken, unfeeling thing, arms spread at his sides in the dirt like he’s saying see this, you're too late. His open eyes are nothing but green glass in the dim light, pupils wide and dark, unchanging as the archangel picks up the flashlight and aims it at him.
“No,” Lucifer says, more faintly than he means to.
Sam’s face is dotted with drops of blood, the left side of his throat a mess of torn tissue that’s soaked in the same dark red. The vamps -- must have been some version of vamps, Lucifer can still smell them, just like he smells Dean and his damn angel -- found the jugular with one quick bite, working fast enough that there was nothing left to do. Lucifer assumes Castiel tried, judging by the marks of an angel blade on the walls and by the bodies that were thrown up and around so hard, they’re nothing but bags of skin filled with fragments of bone.
He clucks his tongue at the bloody marks on the ceiling, sweeps the vampires’ remains away with a snap of his fingers, then sits down to stare at the dead man’s still form. To think.
He uncurls Sam’s fingers to look at the scar on his palm. He remembers what that one’s for. Sam still uses it sometimes, which seems silly; pointless, really, now that Lucifer is truly there, inexorable. But he’s seen him reach for it in the bunker, has followed his gaze down as he tried to look at it without anyone noticing. Has seen Sam go pale whenever he looked up to meet his gloating grin again, even though he knew he would.
He is used by now to how petrified Sam is when they’re in the same room together; has taken note of how hard he tries to hide it. Useless, of course. Sam must know that he can’t hide it from an angel, certainly not from himself. Probably knows that Dean is well aware that he’s white-knuckling his way through it, too. But he tries. Tried.
There’s no fear, now.
Lucifer sits there for a while, fingers rubbing his throat where his grace was slowly drained out of him just hours ago. Nothing there now, but it still stings. He looks down at Sam’s open, brutal wound, cocks his head.
“Maybe it’s sympathy pain, huh, Sammy? We did share a body, once,” he says, and finds that he misses the flinch, the look of hurt and fear and rage in those eyes that now only stare dully, fixed and lifeless.
“Had to go ahead and die just before I got here,” he remarks, fully aware of the fact that his tone is something his father would call petulant. Old news. “Couldn’t wait a couple more minutes? Really?”
His words echo in the space around them, and he can feel the creatures gathering in the dark, pressing against the barrier he’s put up for now, until he decides.
He lets go of Sam’s hand, watches it drop and hit the ground hard, watches Sam’s face for a reaction that he knows won’t come. Sam’s features have only one story to tell, that of his final moments. No one should be less surprised by the concept of violent death than Sam, he thinks, and he knows -- has counted -- all the times in which the younger Winchester wished for death, begged, dreamed about it. But lying here, inside a tunnel that reeks of blood and of rotting flesh and piss and earth and sweat, Sam’s final, frozen expression is one of pure shock.
Lucifer crouches down in the shaft of light below the vent, ignoring the cloud of fine dust that his boots kick up; ignores the way it settles on unseeing eyes and on still lashes. He studies Sam’s face. The mouth, open like he was trying to drag in one last, desperate breath, or maybe cry for help. The eyebrows, still arched in what seems like disbelief. Sam reminds him of the people of Pompeii, their horror encased with them in excruciating detail under the same ashes that incinerated them alive. He vaguely remembers their screams, though he doesn’t recall caring. Not nearly as much as he cares about this. Sam has slipped out of his grip, just as his son did, and it feels as if the entire world has its mind made up to do the same to him, lately.
He claws onto the rage as soon as it begins to bloom in his chest, closes his eyes for a long moment, feels the fire roaring through him again; hears the first wave of night creatures screech and writhe as they burn behind the wall. Others will come in their place. In this universe, too, all things are expendable.
He sighs, places his palm on the dead man’s forehead.
Sam’s eyes are empty of fear, of consciousness, of everything that needs to be there for the plan to work. His lungs aren’t expanding to draw a first, rattling breath. His fists aren’t clenching in the dirt in a blind panic. He remains as he was, cold and silent and unfeeling and indifferent, and Jack doesn’t even care about you, they taught him not to care, this man taught him to forget you ever existed just like Dad just like Dad and your son thinks this is his father.
He grits his teeth, ignores the way the walls shake around him, pushes harder. He’s done this before, it shouldn’t be this hard.
He can feel it when something cosmic shifts, knows when he’s succeeded. Sits back on his heels for a moment, taking long, deep breaths.
Sam doesn’t stir. Doesn't blink. Doesn’t breathe. Not alive yet, though Lucifer knows he’s no longer dead.
“No point in fighting it, Sammy,” he says, and he isn’t sure why his voice sounds unsteady. Probably just the garbled echoes. “You're gonna have to come back this time, too. Might as well get on with it.”
He thinks of the Cage. Of all the times he brought Sam back. It got harder and harder near the end, when Sam was adamant on ceasing to exist, when there was nothing left of him other than pain. Fewer and fewer things worked. And then just the one.
He lowers himself until his mouth is a mere inch away from the unmoving man’s ear. Brushes aside a lock of blood-stained hair. His voice is steady this time, smooth and easy.
“If you don’t come back, Sam, and take the deal I offer you, you know who I’m coming for next. And I saw his face; he won’t make it this time without you.”
He moves back to the corner and watches for a sign that Sam is dragging himself back from oblivion.
When Sam finally does take his first breath, it’s a violent, agonized sound like an inhaled scream. He struggles to sit up, then somehow manages to pull himself up and stand on shaky legs; presses a hand to his throat, where there’s only healed skin and dried blood now. His panicked eyes dart around, no doubt looking for the vampires that were the last thing he ever saw. Ever would have seen.
It’s then that he realizes where he is. Who is there with him.
“No,” he says, and Lucifer thinks to himself that sometimes, humans are so very predictable.
“You brought me back.” Sam says the words like an indictment. There’s disbelief in his voice, and the archangel was expecting that, too. But there’s something else in there he can’t quite recognize.
Lucifer has never been as good at reading human emotion as he is at mimicking it, and so the term heartbreak doesn’t occur to him until Sam breathes out his next, pained word.