When Harry wakes the first time, it's to faint screaming and the stench of a potion being forced down his mouth, which is numb. He stares blindly up at the person giving him the potion, realizes that someone has taken his glasses off and that he hurts, and he struggles, faintly wondering if he's been captured, if this is finally it, if the Death Eaters are finishing Voldemort's job. There's a roaring in his ears, and he can't understand what's being said to him, but he feels hands pinning him down and the soft stroke of calloused fingers against his face, against his scar, which burns and aches and as he tumbles into unconsciousness again, he thinks, Oh, god, I didn't kill him.
When Harry wakes for the second time, he is in the grip of a nightmare, throat working against a scream of his own, the restraints on his wrists biting into his flesh deeply as he surges off of the bed. He feels the tickle of charms against his skin, wonders where he's at, and cries out for Sirius; in his mind's eye, he's watching over and over again as Grimmauld burns, as Death Eaters surge across the lawns of the hidden house and prey upon Sirius' sleeping, helpless body. It's a horrible sight, watching as they peel layer after layer of clothing away from the man's body, and it's not until the touch of the first wand to his skin does Sirius wake and his eyes are lined with blood, a Firewhisky bottle in his hands as he pulls Bellatrix Lestrange into an embrace and laughs a high pitched laugh that skates along Harry's frayed nerves like ice on fire.
There's a voice in his ear, and it's soft and sounds just like Sirius, but Harry can't be sure and cries out again, calling for Sirius, praying that the man is, indeed, there; he's not quite sure where here is and claws at his restraints, eyes flashing uselessly in the dark room. He tumbles back into sleep as something sharp pricks his arm and he has a brief second of coherent thought and realizes that Madam Pomfrey is beside him, wand out and eyes bright with uncharacteristic tears.
When he wakes for the third time, it's daytime, Sirius is beside him, smelling of liquor and smoke and Harry's eyes close against the light as he struggles to whisper Sirius' name. He doesn't quite manage it and when he tries to reach for the sleeping man he realizes that his wrists are tied to the bed and the skin around the ties is bruised—Sirius hears the noise and wakes quickly, eyes darting around him, taking a few moments to realize that Harry is awake and looking him in fear, wondering if this is all a dream.
There's pain in Sirius' eyes, but he's sober despite the lingering smell of liquor; Harry wants to ask how long Sirius has been there, how long he's been here, wants to ask so many things and can only manage a dry, "Please," as he holds up his wrists.
Sirius removes the restraints and says nothing as he does so, stroking the tender flesh beneath his fingers with a touch that borders on painful for Harry. He brings Harry's hand up to his face and kisses the skin gently, ignoring Harry's hiss of pain, and it's hours before Harry notices the scratches, the burns, the scent of magic and guilt that clings to Sirius like a fog beneath the liquor.