Quirrell sits in his cell in Azkaban, plotting his revenge. 'I'll murder Voldemort. I'll take that pale neck of his and twist it off with my bare hands,' he thinks, and far, far nastier things. 'That shithead sucks out my soul and has the fucking audacity to leave me in this hole." The convict might have cried in frustration, but he's dried up and the shock and sadness of his "best friend"'s betrayal turned to contempt, then full-on hatred. He hated that man with every fiber of his being. He will end Voldemort if it's the last thing he does.
He picks up a razor blade for the umpteenth time that day (or hour or minute-it was impossible to say) and fiddles with it. He wonders how long it had been in the room, how many prisoners it had seen, and how many of them had used to tool to off themselves. He had tried, too, to harm himself beyond repair when he had first seen it. He had the scars to prove it. They just tied up his limbs for a week and left him in the same room. Now, he etches a carving onto the stone walls. It was a picture of a flower, something he missed so much about the outside world. The ex-professor looked at it and calmed down. It was dark, but he could still make out the rest of the garden he had drawn. He put his hand to a horribly drawn daisy and crossed it out with several big x's. He threw the blade across the room when the door opened.
A dementor walked in and the lanky man braced himself for the torture.
"No," the dementor says. "You are free to go. You've been proven innocent." The creature nearly spat at the man, who glared back, not believing, but complying anyways.
Quirrell stands outside of the prison, by open water. He would have found it refreshing long ago. The dementor hands the man some clothing and his wand before telling him that Voldemort is dead and disappearing.
"DEAD?!" the scrawny man shrieks to no one in particular. He skips some stones and breaks down in frustrated tears. He had waited so long to get his revenge and the guy just leaves before he gets the chance. Voldemort. It's just like him to get his hopes up and then fucking leave before he can do anything. Fuck him.
"Hey you," a familiar gravelly voice calls out, sounding expectant. Volemort hadn't seen his best friend in a long time, and it shattered what was left of his heart to see his better half on the ground crying, lost, and broken. He wanted to reach out and comfort him when he notices the other man is shaking. He stops himself when he hears laughter.
"Voldemort," Quirrell says in a heap, not looking at the pale wizard. "You bastard." The small man's voice was drenched in bitterness.
"Quirrell?" the former Dark Lord says, gulping. "Look, I know I was a bit of an ass-"
"Ha! A bit of an ass? Really?" Quirrell stood up and pointed his wand at the other man. "No you passed that when you leeched off my fucking soul. 'Ass' is a landmark that you left miles behind when you let me believe you were my friend. 'Ass' was no where in sight when you let that bitch crucio me. You are so far ahead of that word right now that it's nothing but a distant fucking dream to you."
"Look, I'm really sorry-" he was cut off by a wand on his racing heart.
"Sorry doesn't cut it anymore, Voldy. I'm not afraid of going back to that shithole anymore. I'm sure the world will even thank me once they know I got rid of you for good. Avada K-"
He couldn't finish the word, though, because there was a cold hand on his mouth. His wand is taken away by his former friend's free hand.
"Don't do this to me, Quirrell," Voldemort's voice was rising now. Quirrell tries to shake him off and succeeds when his bites the other man's hand. "OW! What the hell?! You know what? I was really hoping to be friends with you again. I had this speech prepared and everything. And now you ruined it, you shit." Voldemort regrets the words immediately. He wishes that he had more people skills. Quirrell claws at his offender's bare chest, drawing blood, and wresting the other man to the ground.
Voldemort uses the wand in his hand and manages to say "Petrificus totalus." The bony man on top of him collapses and hits his forehead on a nearby rock, leaving him unconscious. The pale man sits up and takes a small breath and turns the other man over on his back and sees blood.
"Oh, shit, man. I am so sorry. Oh god, I'm so sorry. Please don't die. Shit. I said sorry. Shit. Everything's a mess. I'm sorry. How did I screw up so bad? Quirrell? Quirrell. Say something, please." The man was crying now, holding his friend towards him. His heart jumps when he feels the smaller man breathe. "Quirrell? Don't leave me, man, you can do this," He stands up and thinks of a location he could go to. "I love you, man," Voldemort whispers to himself.