For those that haven't read the amazing story this is based on, the premise is that post-turn, Orpheus sings a song of grief that slowly freezes the world. Hades tasks Eurydice with stopping it, making a deal with Hermes to either end Orpheus's life or save him, and this is set as he waits for their return.
Hades hears it almost before he feels it, the notes swirling past the unnatural chill down below. Instinctively, he shivers, and were someone there to bear witness they'd guess the space heaters lining his office only provide fleeting warmth—yet another reason to end the cold gripping the world, above and below, as soon as possible.
But that isn't why he shivers. Carried on the wind, from up top straight to his ears, Orpheus's lament of grief and sorrow is unlike anything he's ever heard, and at the same time intimately familiar. Hades knows that ache in his chest of love and loss all too well, knows the fear and doubt that led Orpheus to turn. That was the whole point of the test, he thinks bitterly, downing a cup of whiskey spiked with fire from the Phlegethon. It washes away the cold only briefly, and does nothing at all for Hades' guilt.
Now, since the boy turned, since he failed the test Hades gave, the world freezes for his sorrow. More notes reach Hades' ears, the song that will unmake the world if not stopped, and his breath catches in his throat as a knock on the door interrupts his musing.
"Come in," he says, and the Furies stroll in, smiling ear-to-ear.
"His jealousy rages strong," Megaera says. "His anger is unyielding," Alecto continues. "His storm has killed many," Tisiphone finishes.
"How shall he be punished," they ask at once, and Hades squeezes his eyes shut, not wanting to deal with the question now, if at all.
He's just a boy in love, his wife had said, and with all he's been through, Orpheus has surely suffered enough to avoid the wrath of the Furies. Their argument lacks weight when he considers Orpheus's awareness; for all their talk of anger, his sorrow cuts deepest, like ice to the heart, and Hades knows that if a part of Orpheus is aware of what he's done, that part of him begs for it to stop by any means.
Any means, hence the knife, he thinks. Hades wonders briefly whether Eurydice will succeed in her mission to bring the boy to his senses, or end it in cold steel. As the song crescendos on the wind, causing Hades to clutch his coat ever tighter, he finds he pities them both.
Megaera clears her throat in anticipation, and Hades turns his attention to the goddesses of vengeance. "You will leave him be," he says finally, and they shout their dismay, but Hades raises a hand. "Think of it this way—is what he's done not punishment enough," he asks. The Furies consider this and shake their heads, but he dismisses them with a wave. Let them take out their anger on those who deserve punishment; the poet, for all his faults, is someone to keep an eye on, not grind into the dust beneath their feet.
The Furies leave dissatisfied, and as the iron door opens, Hades can feel the song, louder and stronger than ever. Chills wrack his spine, and Tisiphone gives him a glare as the door closes. If Eurydice doesn't stop Orpheus soon, one way or another, the gods themselves might be lost to his storm.
And yet, as the song continues, creeping through frostbit windows to reach him, Hades can't bring himself to punish the boy. In his lament, in his sorrow and fear, he sees himself every spring when Persephone leaves, every fall in the moments before her train arrives. The doubt and anguish that she'll leave and never return permeates his coal-dusted heart, and before he realizes what's happening, Hades finds himself singing along.
Iron tears roll down his face and his whiskey glass freezes solid in his grasp, shattering into pieces, and he stares dumbly at the broken glass before composing himself. No wonder it's so cold, Hades thinks, with a song like that. Up top it must be unbearable.
He doesn't know whether Eurydice will grasp the feather-light chance he's given and save her love, bringing him out of the cold and dark. But for the poet's sake, the world, his wife, and his own sake, Hades hopes she does.