By the time Harry reached Gryffindor tower he realised he couldn't tell anyone. It took the student body over half the year to stop sneaking looks at the Boy-Who-Lived, and he didn't want them to start back up for the Boy-Who-Shrunk-Snape. Even if some might congratulate him.
"Out late, deary?" the Fat Lady said with a click of her tongue but swung her portrait open for him when he whispered the password from under the cloak. He didn't answer her.
All his roommates were sleeping, and he tiptoed to his bed, barely breathing.
First he stashed Snape in his trunk. Then he remembered being locked up in a cupboard, not allowed to keep the light on, and took him out. Unable to look at him, he whispered, "Sorry."
He shoved him under the bed next, and removed him again seconds later, careful not to jostle him in the jar.
When he turned around in a slow circle, trying to find the best hiding spot that the others haven't used yet for their candy, Neville, and special magazines, Seamus, movement caught his eye and he gawked down at the jar.
Snape was… dancing. Swaying to a rhythm only he could hear, twirling his robe, tapping his boots, and clapping his tiny little hands. He had once watched a dance competition on the telly with Aunt Petunia—well, she watched and he pretended not to while he was dusting—and he swore Snape was dancing the Flamenco.
What?
Harry sank down on his bed and held the jar at arm's length.
Snape paid him no mind and continued to sway and twirl, flinging his arms up in the air and kicking at the grass under his feet. Clean grass. Once he had saved his Professor from a fiery death, Harry had exchanged the burnt ones, imagining he was a good kidnapper that cared for his victim's comfort.
Snape continued to dance, without sparing him a glance, and Harry finally put the jar up on top of his closet and folded his cloak around it, careful not to obstruct the air vents. He had practised with the cloak, thinking he could use it to hide stuff from Dudders, but had learned that it only turned invisible if it detected a human under or in it. He breathed a sigh of relief now when it disappeared around Snape.
"Did you do it?" Ron asked when they finally got up. Classes were done with and there was no hurry so they all slept in, only getting up in time for late breakfast.
"No." His neck had a crick in from trying to not look at the closet.
"Chickened out, did you?"
"No, I didn't! There was nothing in his office, and I didn't know where his rooms were."
"Well, ask somebody."
"I will."
They left, and Harry could hear Dean say he doubted he even went and the other two snickered.
"Whose rooms?" Neville wanted to know and Harry whirled around, having forgotten about the chubby boy. Unlike the others he was dressed already and was munching on a jammy toast that he had brought from the hall.
"No one."
His face fell. "…fine."
Harry daren't look at his closet.
He hung around a while but Neville dug out a box of chocolate wafers and he finally left to go have breakfast himself. Stomach roiling, he was not in the least hungry, but realised he had to feed Snape.
He took Snape to the lake. It was a bright, sunny day, but Harry saw nothing of it. He skulked past students and teachers, hidden under his invisibility cloak, the jar clutched to his chest. There was a secluded spot behind a large hollowed out boulder that he had staked out for himself at the beginning of the school year. You had to crawl under a prickly bush to get there, and then you reached a sandy spot that Harry liked to imagine was a miniature cave, bracketed on all sides by the boulder, the bush and the lake. The spot was just big enough for one person to sit comfortably with their legs stretched out.
He removed the jar from the cloak and sat it down on the sand before retrieving the buttered bun he had sneaked from the hall and set it on a small piece of tissue next to it. Something to drink had been a problem, as you weren't allowed to take dishes out, so he had washed out an old vial in the bathrooms and filled it from the tap. He organised all these now, and all the while his toy sized Professor stood with his arms crossed, watching him with a blank face. Harry was just glad he had stopped dancing.
"I'm going to let you out, sir, to have breakfast."
Snape didn't bother to acknowledge him.
Harry unscrewed the jar and tipped it ever so gently, tumbling Snape out onto the sand. Bugger it. He had thought that would go differently. "Sorry."
When Snape stood but did not move towards the bread, he pushed the roll closer and removed the stopper from the vial. "Water."
Snape ignored it. Instead he squeaked, "What are your plans, Potter? You have me in your power, go ahead, do your worst." He spread his arms, and the dried green glop flaked from his robe.
"Nothing. I-I have no plans."
"Didn't think that far ahead?" he asked sarcastically.
Harry stayed quiet. He hadn't.
"Where did you get that cloak?"
He never got gifts. Old socks, hangers, and pennies didn't count, and Harry had always feared that the cloak wasn't meant for him, even though the note had clearly said, 'Harry', so he bit his tongue.
"Fine. Tell me, what did Weasley mean, 'did you get it'? What exactly were you up to in my office last night, Potter? Stealing?"
"No!"
"Then what, Mr Potter! I'm all ears!"
"It's none of your business," Harry spat out, guilt working his tongue, his stomach in knots; he knew he wouldn't be able to face Snape ever again if he knew about the tests.
"Sir."
"What?"
"It's none of your business, sir."
"It's none of your business, sir," Harry repeated obediently, hoping to appease the wizard, feeling himself in a twilight world where nothing was quite what it should be. He looked on confused as Snape's face twisted into a wrathful grimace.
"And that's where you are wrong!" Snape squeaked. "It is all my business, Mr Potter! I am the one shrunk to a miniature! I am the one being kept in a jar by a delinquent! Who else's business would it be?!"
"I'm—"
"Keep quiet!" he snapped. "Take me to the Headmaster, this instant!"
"I can't!"
He bundled Snape back into the jar and twisted the lid on. Then, to escape the wizard's venomous black eyes, he dragged his invisible cloak over his head. He didn't move though, he stayed in place and watched Snape. Who seemed to know exactly where Harry was, cloak or not, since he watched him back.
They stayed that way for a long time. Finally Snape stepped forward and knocked on the glass. Harry dearly wanted to ignore him but Snape kept knocking patiently until he slipped the cloak from his head, unscrewed the lid, and tipped the jar over.
"Potter," Snape said once he had returned to his feet. "If you let me go now, I will inform the Headmaster that I never saw who did this. I am sure it was a harmless prank and we won't talk about this ever again."
Harry didn't believe him for one minute. "Nice try, sir. You've tried all year to get me expelled; I don't think you'll let this go." He made to return Snape to the jar but his Professor held up a tiny hand and he stopped.
"Think about it. The offer will stand until tonight."
Harry made to return him a second time and again he held his hand up.
"Before you put me back, I need to use the facilities."
"The f…?"
"Turn your back so I can take a piss, Potter."
Oh. He hurriedly turned away, feeling his face heat up. What made him look back a minute later, he never knew, but he yanked Snape out of the lake and stuffed him back in the jar. He threw a piece of the bread roll in after him and slammed the lid on. Then dragged the cloak back over his head.