(Warning: mentions of child abuse)
Harry heard the soft swishing of robes as he awoke and opened his eyes to see Dumbledore pacing slowly. He stopped when he saw Harry was awake and sat down beside him in a conjured chair.
"How do you feel?"
Harry paused a moment, taking stock. "A little better. Maybe? It's hard to tell, but…" He paused, trying to put into words the…solidity he felt. "I think…this is the first time I really feel like…I'm going to live."
Relief was visible in Dumbledore's face. "I've been confident of that for some time now, but it means much more that you feel that way. It also means your body will be receptive to healing a few more injuries.
"You seem to be handling the poison well on your own, which I'm glad to see. So from here, we can prioritize whatever is most painful."
The magical lacerations crisscrossing his back pulsed—almost mockingly, Harry thought—with agony. But concealed beneath those wounds were older scars of a muggle origin, given by the various instruments Uncle Vernon favored for beating his nephew. Scars he had never shown another living person.
So instead, Harry asked, "Is there any way to help the cruciatus curse?"
Dumbledore's face darkened with momentary fury, but he regained composure a moment later. "A spell can help, and it won't take much strength from your body, but time, I'm afraid, is the best healer for that."
Harry nodded in understanding. Dumbledore placed his right hand on Harry's forehead and murmured a spell.
His bones, his muscles, even his skin breathed in relief. The aching was still there, but more distant.
"Thanks," he said.
"Do you need to rest some more, or are you up for more healing?"
Harry hesitated, and he knew those piercing blue eyes gleaned something from his reluctance.
Dumbledore ventured cautiously, "There are bloodstains on the back of your shirt."
Harry hesitated. He didn't want Dumbledore to see the scars he'd so meticulously kept hidden for so long.
"I'll make it hurt as little as possible, I promise, and it will feel much better after."
Finally, Harry nodded. He was past caring about so many things that had once seemed so important.
"Do you think you can sit up?"
Harry tried weakly, and Dumbledore supported most of his weight in helping him.
He tried to take off his shirt, but gasped as the cuts stretched and shards of sharp pain stabbed through his back.
Dumbledore put a hand on his arm to stop him. "Harry—don't."
Harry held still as Dumbledore took a knife from his robe and gently, slowly, cut away the shirt, using his wand to separate the cloth from the cuts, now dried together. Harry tried to keep still, as each wince brought a splinter of pain through his back. At moments he found himself wishing for the numbness of when he was first rescued, but each time he checked himself.
Finally, the skin was bare, and Dumbledore let a shower of cool, cleansing water fall over the cuts, clearing away the dried blood, the dirt, and the grime.
Harry braced himself for the headmaster's reaction. Sure enough, he heard a sharp intake of breath.
"Oh, Harry…"
He didn't have the strength to respond. Even if he had, he didn't have anything to say. Dumbledore healed the fresh, magically-inflicted wounds one at a time, conjuring bandages over the deeper ones that held onto the Dark Magic more tenaciously. Harry relaxed ever so slightly with each drop of relief. The older scars he knew would still be there. When Dumbledore finished, Harry felt a new shirt appear on him.
Dumbledore sat down opposite Harry. He said softly, "I have to ask, Harry."
"I know." Harry studied the carpet, willing the tears not to come.
"Harry, look at me."
With the greatest of efforts, Harry raised his eyes to meet the headmaster's. Seeing the weariness and sorrow in the old man's face broke the last barrier he could maintain and tears poured down his face. Dumbledore took a handkerchief from within a pocket and held it out.
Harry took it, too exhausted to feel embarrassed.
Dumbledore gave him time to wipe his face, then prodded gently, "The Dursleys?"
Harry could only nod.
"Your uncle?"
Another nod.
"Your aunt?"
"She never beat me." Harry heard in his own voice that he thought no better of her for employing a less violent form of cruelty.
"Dudley?"
"He couldn't hit as hard," whispered Harry.
"I am so incredibly sorry, Harry," Dumbledore said in a shaky voice, and Harry looked up to see in surprise tears pouring down the old wizard's face. "Had I had any idea what was happening…"
"How could you not have known?" Harry cried desperately, anger and exhaustion making his voice hoarse. "You've known everything that's happened to me, made every decision that's controlled my life—" His voice broke.
"You have every right to be angry with me. I am as culpable for not knowing that they hurt you like this as if I had known. Time and again I have put you through unimaginable suffering. I ask only that you try to understand that…every time I did so, I had your best interests at heart, and I have only ever tried to protect you, however poor a job I have done of it on too many occasions.
Still staring at the carpet, Harry whispered, "I'm not mad at you, sir."
Dumbledore sighed. "You are admirably willing to forgive, Harry, but I know you are still hurt by what I did, and I can only ask that you let me help make it right."
"I just…wanted a family so badly." Harry's voice broke as another wave of tears overcame him.
Dumbledore reached out and gripped Harry's hand. "You do have a family, Harry," he said fiercely. "But you have every right to blame me for living without one for eleven years."
I know the Dursleys-abusing-Harry is a somewhat overdone trope in fanfiction, but I couldn't resist. This is a departure from canon (though the Dursley's treated Harry in an inexcusable way and, in Dumbledore's own words Harry faced "neglect" and "even abuse" in their house, he didn't come away with the kinds of scars described above), but I felt that it fit in with the story, and I've always wanted to write my own version of Dumbledore confronting his decision to place Harry with the Dursleys.