Wordless magic. He'd learned it. Occlumency. He'd learned it. Duelling and silencing and tracking and warding and healing and keeping his screams of grief and building madness so deeply buried that they didn't even show in his eyes. He'd learned all of it.
But now Snape stood over him, Harry's wand in his hand, and the trademark sneer on his face as the rain came down. "Not good enough, Mr. Potter," he said, his ugly face twisted and triumphant. "Do you think the Dark Lord and his followers will duel like a set of temperamental second-years? Shouting insults and crude blasting hexes from afar?" He leaned close, caught Harry's shirtfront in his hand, and hauled him from the ground with a shake. He put his nose hard against Harry's own, and his breath was foul as he sneered, "You have no more little friends to take your lumps for you. All your brave protectors are occupied with staying alive. If you wish to defeat the Dark Lord, you must do better."
And Harry laughed. It was a genuine laugh, and it felt good to let it go. Snape shook him as the sound began to grow sharp, hissing for him to be silent, but he didn't. He couldn't. The dam of his months-long silence had been breached, and not even Snape's nose was big enough to block the words up.
"No, Snape, I don't have to do better. I don't have to do better at all."
Another shake. Another snarl, this one spiced with a flicker of fear in those black eyes. "Stop babbling, you fool, and listen to-"
"I don't have to do better," Harry explained carefully, "because I am not going to win. I've taken all the horcruxes. Every one of them."
"Yes, I realize you've been lucky enough to destr-"
"Haven't destroyed them," Harry said, feeling the strange twist on his face that some distant muscle memory identified as a smile. "Not going to. Just hid them away where no Wizard will ever manage to find them. Now all I have to do is find Vol. Dem. Mort," he spat the syllables into Snape's horrified face, just to watch the man flinch. "And then I die. And then the Wizarding World will get just what it fucking well deserves."
"You..." Snape gulped. "You're mad."
"Most likely," Harry agreed. "I'd have to be mad to allow a bunch of bastards to burn up my childhood fighting their war because they couldn't be arsed to fight it on their own." He leaned closer to Snape, whose fingers were loosening on Harry's shirt as he leaned away. "Bet you wish you hadn't killed Dumbledore now, don't you?"
Snape shook his head, at last recovering his footing. "If you haven't the wit to see through the obvious, I do not have time to explain myself to you."
Harry just stared at him. Waiting. Lighter than he'd felt for nearly a year. Almost done, that was what it felt like. Very nearly freedom. And the very best revenge he had ever imagined.
Snape was nothing though, if not predictable. "So this is where Gryffindor nobility leaves us?" he asked. "You betray your mother's sacrifice? Hagrid's? Albus'? The Weasleys and Granger? Did Black, and Lupin and Tonks die for no reason, just because you can't be bothered to learn your lessons-"
And that was when Harry shot him. The recoil jerked the gun from his pocket, and Snape fell to the ground, howling and clutching his leg with both hands.
"Didn't say I couldn't kill him," he told the man in a low, calm voice. "Just said I wouldn't. You Wizards spawned him, you took his mark and put him in power, so I figure you bloody well deserve him." He kicked Snape's wand toward the rain gutter as he turned to walk away.
"Potter, don't do this." It must have been the pain that made Snape sound like that. Attention caught, though, Harry did glance back. Snape was reaching out, bloodied palm turned upward in supplication. "Don't just give up like this. I can teach you how to win. You don't have to throw your life away. I can help you beat him!"
"Or you could do it yourself," Harry shrugged. "You're an old hand at murder, after all. Much better at it than I'll ever be." Snape looked down, let his wet hand fall. "Tell you what," Harry mused, nodding a wordless healing spell at Snape's leg. "I'll give you a week to get it done. Then we'll talk."
Harry walked away then, feeling the lessons of the year settle into his skin like the rain into his clothes. Hatred, he'd learned it. Revenge, he'd learned it. Pitilessness and cruelty and loss and bitterness and futility and twisting the hope of the hopeless into a deadly weapon, then beating them down with it.
All things considered, Snape really wasn't all that bad, as teachers went...