Here's the second of the two mini-chapters!

"Please— it's just a little further!"

Quirrell ran for the safety of his small apartment, his hands clasped tight over his turban. Beneath the fabric, Voldemort thrashed and bit, his half-formed lungs heaving with fury as he screamed, the sound escaping Quirrell's fingers like steam from a boiling kettle.

He plunged headlong into a small postern behind the greenhouses, stopping only long enough to slam the door shut behind him and throw the bolt. Darkness closed around him as his eyes struggled to adjust to the sudden gloom, but he dared not linger. He groped towards the narrow staircase at the far end of the entryway, gasped as a low bench cracked against his shin, and then gasped again as Voldemort retaliated with a spike of malice that set his nerves sparking like live wires.

He collapsed against the stairs. "I'm sorry! I'm sorry! I'll be more careful— just please, don't do this here. We'll be caught."

Voldemort snarled, spat out a garbled mix of Parseltongue and English with no discernible meaning, and continued to tear at the thin layers of cloth containing him.

Quirrell reached up, grasped the bannister with shaking hands, and hauled his body up one step at a time.

Ever since they fell victim to the spell in the headmaster's office, the connection between them had frayed. Quirrell was no longer at the mercy of Voldemort's emotions, but what little seeped through was jagged and discordant, biting like the teeth of a saw thrust deep inside his chest.

He staggered to a landing opening onto the first floor and leaned against the wall, screwing his eyes shut as he wiped his mouth with the back of his hand and panted for breath.

Voldemort wasn't the only one to suffer from their near separation. Awareness of the damage crept upon him with each passing night: a sense of fragmentation, of cracks forming in the foundation of his being. He could no longer cast magic with the same innate ease he once did — even cursing Potter's broom during the match had left him wan and shaking — and he feared it was only a matter of time before he shattered.

Potter…

The dim landing spun around him, and he pressed a hand against his mouth, gagging.

He hadn't meant for Potter to fall. Indeed, he hadn't even known the boy would be playing until Snape jerked like a fish tossed into a hot skillet and turned on McGonagall with an expression so comically outraged it cut through the haze clouding his mind enough for him to recognise the small, unexpectedly resilient child in the Gryffindor team's lineup. Potter looked so tiny — a sparrow among eagles. The juxtaposition made him smile, feeling almost wistful as he watched them mount their brooms.

If he had known what would happen after the announcer bellowed Potter's name for all to hear, he would have left before the teams had taken the field.

He'd attended this match as a distraction. A way to forget, for a time, the looming spectre of Voldemort's wrath. The dark lord had been quiet since Samhain, but he would not lick his wounds forever. Eventually, there would be a reckoning for Quirrell's bungled reconnaissance of the headmaster's office. Not only had he failed to find evidence of the Philosopher's Stone, but Voldemort had been injured when the spell he'd stumbled into tried to tear them apart. It was a failure that could not be forgiven, and Quirrell's dread had grown every day the dark lord remained silent.

After two days, he began to wake in the night, trembling and drenched with sweat as terrifying visions of torture and death assaulted his dreams.

After five days, Professor McGonagall had pulled him aside in the staff room and asked if he was ill.

Bitter laughter crawled up Quirrell's throat. If she could see him now, bent over and dripping sweat in some godsforsaken corner of the castle, she wouldn't need to ask. His poor health was obvious in the bruised skin ringing his eyes and the tremors running rampant along his limbs. And he was ill, but the sickness that plagued him was guilt, and there was nothing she or anyone else could do to ease his suffering.

He pressed a hand to the back of his head, his knuckles shining white as they tightened around the face writhing beneath his turban and pulled — tried to rip the accursed thing from his body — but it wouldn't budge. He'd let the dark lord in, and in doing so, had sealed his own fate.

"Curse his broom."

He shuddered at the memory of the order Voldemort had whispered in his ear as Potter dodged an oncoming Bludger and darted away from the rest of the players.

"Now, Quirinus!"

Obedience had won out. He'd raised his hand, his wand hidden by the blanket wrapped around his shoulders, and cast a curse of frenzy. He felt the spell connect and watched the distant speck of red dart erratically across the sky while terror at what he'd done drained all conscious thought from his mind.

The boy fell… and then, inexplicably, the boy flew.

It was at that moment that Voldemort had gone mad.

They'd barely escaped before his hissing and spitting was noticed by the other teachers in the box, and even now they remained vulnerable.

The postern door rattled as someone tried the handle, the sound echoing up the steps like the clatter of chains. Quirrell lurched forward, threw himself up the two remaining flights of stairs and darted into his rooms, bolting the door behind him.

"That traitorous scum!" Voldemort howled, as Quirrell tore off his turban and tossed it aside. "I should have killed him the night he begged for that wretched woman's life. How dare he teach her child MY spell?"

Quirrell walked across the faded rug and sunk into his armchair. A fire crackled merrily in the nearby hearth, but he could not feel its warmth. He pulled the blanket closer around his shoulders and wondered if he'd ever feel warm again.

"It was Snape! He must have taught him— all the others are imprisoned— it must have been him— I knew he'd betrayed me when I saw him working for Dumbledore, but I had hoped— yet he dared to give away one of my greatest achievements to Potter— who else did he teach?— Dumbledore? Does Dumbledore know? WOULD HE DARE?!"

Quirrell clasped his hands over his ears, but he couldn't block out Voldemort's mad raving.

"He must be silenced!"

"Snape?" Quirrell gasped. "But the aurors… and Dumbledore is already suspicious, if something happens to Snape won't he—"

"He will be silenced! Do not think I've forgotten your recent failures. You have not even found me one of the snakes that boy released into the castle!"

"I-I'm sorry. I will try."

"You?" Voldemort laughed, high and cruel. "Snape may be a traitor, but he is still one of my marked. He'd take you apart like a doll before you'd even cast your first spell. But don't fear, for I will teach you a way to borrow the hand of another."

Quirrell pressed his hands to his face. He didn't want this — didn't want any of this. Killing children. Killing his coworkers. The dark lord had often spoken of destroying his enemies, but the reality of what that meant hadn't sunk in until he'd watched Potter plummet towards the ground.

It was worse than robbing Gringotts. Worse even than letting the troll loose inside the castle.

He had to make amends.

Quirrell raised his head and met the gaze of his reflection in the mirror next to the door. He looked like a whipped dog. His face was pale and drawn, his eyes bloodshot and a small tick jittered the corner of his lips. He licked them, running his tongue along the edge of his teeth.

Snape was a devious man and a powerful wizard. He wouldn't prove an easy target, even with Voldemort guiding his hand. As long as they didn't catch him by surprise, he was unlikely to die, which would force the dark lord's vendetta to drag on, perhaps for months… and each month Snape distracted Voldemort was a month Potter would be spared the wraith's attention.

Quirrell closed his eyes. Forgive me, Severus. I know you dislike the child, but right now, you're his only hope.

"Well?" the dark lord snapped.

Quirrell straightened his back, sat up. He took a deep breath. "I will do my best."

Across from him, his reflection smiled grimly.

I will do my best. But not for you.

So, the reality of having an unhinged dark lord in his body is finally sinking in for Quirrell, and Snape's facing a karmic reckoning for all the times he made small children cry.

I'm going to try and keep future chapters to a more manageable length, because it seems anything over 10k words causes me to stall and leads to things like the yearlong gap between Part of You and The Bucking Broomstick chapters. In any case, next time Harry will learn the results of his broom's analysis and rightfully decide that if there's someone in the school trying to assassinate him, he needs a lot more allies.