A/N: Here's my contribution to the festive season, perhaps somewhat lacking in the Christmas spirit of joy and what not. Merry Christmas and Season's Greetings to everybody! Title comes from Yeats.

Warning: Slash, incest, underage, possible dubcon. Y'know, your average festive cheer.

Because it is always at Christmas that the old ghosts cry out louder.

Like An Old Song

The house is always coldest in winter, ice lining the outside windowpanes and damp crawling from the dark corners of rooms and spreading to consume the entire household, shadows creeping through the upstairs hallways and curling beneath doors. Sirius moves through the house as a lonely ghost, his bare feet recoiling from the chill of the wooden floors, and even with the house full for the Christmas holidays there are empty echoing places that call out to him and settle frozen in his chest, tugging at his aching heart. He presses his forehead to the cold glass of the drawing room window and breathes a smudge of hot air from his mouth as he closes his eyes and remembers.

The whine and fall of music swelled through the heavy air scented with festive spice and the undulations of voices rippled around the room; Sirius danced with Bella, his hand curled around her waist and her long fingers digging into his shoulder, and the wine that had been served with dinner made his tongue feel heavy and his head spin. The dancing pools of light reflected in the ceiling-high mirrors and the round body of the Claret blushing circles of red in his heated cheeks so when he glanced his whirling reflection his face was flushed and his eyes blurred with the bright jewels of light spilling from the high chandeliers. And in the corner, Regulus stood, watching over the rim of his goblet, watching his brother's dark hair fall into his burning eyes; and Sirius could feel Regulus' eyes sliding over his back and felt the familiar sick rush in the pit of his stomach, felt like he was falling.

In the evenings, Sirius can taste ice on his tongue and he likes to watch Harry from across the room; he likes to look at the boy's white hands and narrow hips. And in those twisted moments Sirius thinks that the wail of music and the ring of laughter is alive again or maybe it is that the sad ghosts are smothered into silence, he can't tell, can't tell because Harry is quiet and holds so still when Sirius's hands skim over his body, touching him in places that Sirius probably knows are wrong but likes to pretend he doesn't. Sirius corners his godson in dark rooms and whispers to him, lips rasping the haunting words of a broken man, and he turns his eyes blind to the way Harry's fists clench convulsively by his side and how his jaw is held tight.

And later, pushed up against the wall in the library, and through the window the blue light of winter milky and pearlescent and casting shifting shadows in the darkened room while the low tremulous quiver of violins cried from below, muffled by the polished wooden floors and thick carpets imported from the east, Sirius pressed his mouth to Regulus' throat and touched his palms to his brother's trembling thighs. Outside, the first snow began to fall and softly drifted against the window as Sirius' cold hands slid against Regulus' burning skin and Sirius remembers how their breath was quiet and wisping as the delicate sheets of frost brushing the lonely London streets.

Sirius remembers the frail feel of a heaving ribcage pushed against his own except now it's Harry pressed against the wall and Sirius thinks it funny how much younger the boy looks in the near darkness, the dim light softening the deceiving strong line of his jaw that belies his real age in the coldness of bright light. Sirius strokes his fingers along the back of Harry's neck and breathes close to him, hoarse rasps against the hollow of his collarbones, and he smiles brokenly into the curve of Harry's neck as he presses his palm to Harry's erection and the boy gasps quietly. His hands fumble with the front of Harry's trousers and his fingers feel numb with cold even as they curl around his godson's burning cock; and Harry whimpers and chokes over strained noises of desperation as his body twists and his hips jerk. And when he comes, Harry hisses through his teeth, Sirius, and Sirius almost wants to laugh at how anger clings to the strangled whisper like dark treacle.

Sirius, Regulus breathed, Sirius Sirius. His voice stuttered and slurred and Sirius answered back with a matching tremble in the moans curling from the back of his throat like thick smoke or the coil of cold breath on icy mornings. Sirius' fingertips left burns of red across Regulus' white skin, marking him and tainting him, and his little brother's mouth was a smudge of raw crimson in his open face as his head fell back against the wall with a soft thud.

Sirius slowly steps away and watches through unfocused eyes as Harry fastens his trousers, head bowed and mouth a strained line as he breathes hard. Harry won't look at Sirius as he silently turns and flits from the weight of the darkness pressing in on the room, the door thudding weakly behind him; but Sirius doesn't notice because he is trying to remember what happened next, trying to remember how he pulled his brother down to the floor and how Regulus' small hands trembled at the small of his back. He tries to remember but his mind is black and the room is cold and the window is vacant of soft snow. He stands, swaying faintly, and in the back of his mind he hears the dying notes of the last violin, crying out to the empty house.

Peractio