Draco was left stewing in his own thoughts for days after that. He'd tried to avoid the only possible conclusion for ages, but eventually he realized that Mother was indeed right. He'd behaved abominably. He'd disgraced the Malfoy family, not necessarily with his actions, but with the boorishness and lack of subtlety they'd been conducted. And he called himself a Slytherin! No, truly Malfoys had a noblesse oblige to those lesser than them – which meant practically everyone. It was time to live up to that.
He was there when Harry woke up. "Harry – uh, Potter," he said, as soon as Madam Pomphrey had given Harry an examination. "I am…um…" How exactly did one apologize for so many years of bullying? "I am sorry…for treating you so harshly. My mother informed me it was not a proper way for Heir Malfoy to act, and I apologize."
Harry looked entirely skeptical. "So basically what you're saying isn't that you're sorry for acting like a berk, you're sorry your mum caught you."
Draco's face twitched. "Listen, Potter!"
"Thought so."
Draco forced himself to calm down. "Just…you can believe what you want. It doesn't matter. The apology is given. Reject or accept it as you please. I owe you a life debt for saving me from that monster. That means I owe you a favor."
Harry smirked and a chill went down Draco's spine at the sight of it. What horrible, humiliating things would Potter want him to do? Streak naked in the Great Hall? Kiss Granger? "I want you to leave me and my friends alone," Harry finally said after keeping Draco deliberately in suspense for the better part of a minute, the bastard.
Draco blinked. "Wait, that's all?"
"Do you have any idea how much you've made our lives miserable over the last couple of years?" Harry demanded. "Making fun of us constantly? Insulting our parents? Getting us in trouble?"
"You were only in trouble because you broke the rules, and I got in trouble too!" Draco argued, almost instinctively. He took a few deep breaths. This was not the time to argue. "Fine. I leave you and your friends alone. Your friends being defined as…?" If Harry was going to do something dumb like placing every student at Hogwarts under his protection, then that was not bargaining in good faith.
"Hermione, Ron, and Neville."
Draco arched an eyebrow. He would have thought Harry had more friends than that. "Agreed. I will act civil with you and your friends and the debt is settled." He held out his hand and after peering at it for a few seconds suspiciously, Harry took it.
For the rest of the year, Draco kept his word. He avoided Harry and his friends whenever possible, and when not possible, he tried to be polite, if rather aloof, towards them. Of course, the other Slytherins still picked on them, perhaps even harder to pick up the slack for Draco, but that was not Draco's problem. He had not instigated the incidents and stopping them fell outside the purview of their agreement. It was slightly shocking to learn no one in Slytherin resented him for his new cordiality towards Potter and his ilk, but the news that it was because of a life debt seemed to stop most objections.
At the end of the year, there was apparently some hullabaloo about Potter facing off against a horde of dementors, Sirius Black, and their werewolf Defense Professor (Draco had never trusted the man), but Draco dismissed it as hogwash, product of the notoriously unreliable Hogwarts rumor mill. He knew very well from personal experience how the truth could be distorted; he'd started a sizable chunk of those rumors himself, after all. Draco hadn't made any steps towards befriending Potter, but he decided he would wait until the next year, when there wasn't a murderer lurking around and Potter wouldn't nearly be as stressed.
As always, Mother picked Draco up from Platform 9 ¾ alone. It was beneath Father's dignity to do so and Draco had tried his best to ignore how bad that made him feel. A lot of things regarding Draco were beneath Father's dignity, it would seem. But unlike the last two times, Mother had not taken Draco back to Malfoy Manner by means of apparition. Instead, she practically dragged him to the Muggle entrance.
"Mother, what are you doing?" Draco demanded. "That's where the Muggles are."
"I am teaching you a lesson, Draco," Mother said serenely. Draco's mouth dropped open. Was he being disowned as Mother threatened? Was he being sent to live in the Muggle world? "Relax, my dragon. You are not in trouble. I am pleased you have taken steps to deescalate matters between you and Potter. I would have preferred you made more progress in befriending him, but it is a step in the right direction."
Draco breathed a sigh of relief. "I've been trying my best to behave in a manner befitting my station, mother."
"And your efforts are not unappreciated," Mother said with a fond smile. "No, we're going on a little trip to teach you an important lesson. Perhaps, if you try, you may even find yourself enjoying yourself." Draco completely failed to see how spending time amidst the filth of Muggles could ever be a source of enjoyment. "Remember, whatever you do, the Statute must be upheld." Draco nodded. "Good. Let us depart."