Notes: The title is taken from a line in Paradise Lost. I have included a few bits of dialogue from season 5 episode Hammer of the Gods. You'll recognise them when you see them.
Warnings: Very brief, non-graphic reference to self-injury in the third to last paragraph.
"Horror and doubt distract
His troubled thoughts and from the bottom stir
The Hell within him, for within him Hell
He brings..."
Absolute silence. Darkness. A never-ending expanse of shadows. They writhe in the air, vast pockets of emptiness amidst an icy blue glow, fracturing the light. A feeble pool of illumination spills across the ground.
Lucifer drops to his knees, feels the scrape of rough stone against his denim-clad legs. The chill emanating from it seeps through his clothes. He stares down at his shaking palms, at the familiar crisscross of lines that pattern the skin. The tiny slash of a silvery-white scar that curves around the base of his left index finger. His hands, tinged with all the pallor of a corpse beneath the flickering light. His previous vessel's hands — how?
Never mind. The how does not matter. What matters is the where, and the where... Lucifer's fingers curl unbidden into fists. He had tasted life again, the sweetness of freedom and the corruption of humanity cloying on his tongue, and now he's back in the Cage, this desolate, forsaken tomb. Back in the prison he spent millennia confined to. The stolen heart in his chest beats out a ferocious rhythm, pounding against his ribs.
From eons and light years away, Michael screams. That anger, that oh-so-righteous fury, rattles the very foundation of the Cage. The Devil sneers. His brother keeps shouting, slipping into the Old Tongue as he spews vitriolic condemnation. Beneath the fury lies terror. It bleeds into Michael's words, the demands of, "Is this what You wanted of me, Father? Is this to be my recompense for my faith?"
So pointless, Lucifer thinks. After all, he spent centuries raging at their Father when he was first cast down; he never received any answers.
Michael's voice rises, the name he chokes out reverberating through the Cage. "Gabriel," he says. The anguish of it crashes into Lucifer like a physical blow. "Our brother, Gabriel—"
The shadows twisting around him coalesce while Michael mourns, until they form the solid walls of a room that still haunts the darkest corners of Lucifer's mind. From his kneeling position on the ground, he watches his memory-self turn. Sees the blade sink into a greyscale torso. Hears his voice murmur, "Don't forget. You learned all your tricks from me, little brother."
Lucifer slaps his hands over his ears. Stop. Stop, stop, stop.
The memory freezes on an image of coal-black wings spanning the hotel floor. An eternity later the room begins to quake, then dissolves, scattering back into obscured shadows. One deep breath, and they come together anew. A flash of metal; eyes wide with shock; regret curdling his stomach; a rendering of wings. Over and over it plays, in a vicious loop that he sees even when he closes his eyes.
The last scene cuts out. Pause and reset, and this time he finds himself standing, no longer a mere observer.
"I know where your heart truly lies," Lucifer says, the words spilling from his lips despite how he tries to hold them in. His fingers grab the blade as he turns; he guides the weapon into his brother's flesh. "Here." Then the body collapsing against his arm warps, its features melting and distorting. Suddenly, it's Sam staring up at him — Sam's horrified face, Sam's mouth gaping around a silent gasp.
Lucifer exhales, the breath ripped from his throat as he stumbles backwards. There is no burst of light, no explosion of Grace. Blood blooms across Sam's shirt. A smear of black that spreads and spreads and spreads, until finally, he falls.
The altered memory swells to life again. A sick, unfathomable madness grips Lucifer tightly. It refuses to let go, so he claws into his borrowed skin, digs furrows in his arms with too-blunt nails. Flesh splits in bloodless gashes, disintegrating as the atoms themselves disconnect and flit away. No physical pain comes from destroying himself, which fills him with a rage so thick it chokes him, makes his body tremble. Then Lucifer blinks, and he is whole once more.
The Elysian is gone.
Michael is still screaming.