"I see you still have no end of dunderheaded ideas," Snape grumbled, shooting Harry a mutinous glare. It might have been more effective if his tone had not been so high-pitched, or if he didn't currently stand at a height just below Harry's shoulder.

"I'm actually starting to think this was a great idea," said Harry.

"You would," sneered his former professor. "Just look at me, Potter! This isn't even how vampires dress. And don't think I don't know the exact reason you bought this abomination for me!  A vampire, Potter? Really? And I thought you were supposed to be the adult, now."

To his credit, Harry tried not to look amused – he really did – but quite frankly, Snape looked a bit adorable. Especially furious.

"It's just temporary," Harry reminded him.

Snape scowled, and again it was ineffective. It just was no easy task for an 8-year-old to look menacing. "If the antivenom had been brewed properly, I wouldn't be in this mess," he declared.

"It was brewed properly. It was brewed exactly to your specifications, in fact. Just be glad we were able to find the recipe," the eighteen-year-old stated. "You could be dead, right now."

"Well, I would rather be bitten by Nagini again than parade around with you dressed like this," retorted Snape.

He didn't mean that. Harry knew he didn't mean it. He had been there after the man had been bitten by Voldemort's snake, had seen the flicker of horror and regret in the man's eyes as he faced his end, even as he gave Harry the memories with the knowledge he needed to end the war.

It had to have been unintentional that Snape included the antivenom to Nagini's bite in those memories. His subconscious must have included it, a sort of silent cry for help, but Harry had heard it. Locating where Snape had stashed the potion's recipe among his notes had taken so much time that Harry had feared that they would never find it or that the Potions Master had merely planned to develop the antivenom but had not in truth managed to do so.

Even after they had gotten the potion brewed, they weren't confident that it would work. "He's already gone, Harry," Madame Pomfrey had tried to tell him. "This long after he's been bitten… His body's already cold – he's dead." But Harry had insisted that they try. After all, if there was no chance, then what good was a cry for help? If death were inevitable, not even Snape's subconscious would try to fight it.

So they had fed the potion to the man's still form. The woman had been shocked when he actually swallowed. By some miracle, or perhaps forgotten design, the Potions Master had entered something much like the Living Death, undetected by the mediwitch's most advanced diagnostic spells. Had Harry not pressed to give him the antivenom, he really would have been dead.

They still hadn't determined just what had caused his deaging, however, just that it was temporary. It certainly wasn't temporary enough for Snape.

"Here, take the bucket," Harry said.

Snape eyed the white glow-in-dark pail with disdain. It was meant to look like a ghost, but the miniaturized Potions Master just thought it looked absurd. "I am not carrying that," he sniffed.

"Just for a few houses," his companion cajoled.

"Why should I? It wasn't my idea to go trick-or-treating."

"I've never gone trick-or-treating before."

"Then go by yourself! Why must you drag me into it?" That was definitely a whine, although Harry knew the professor would never admit to it. "Why do you even celebrate Halloween? Shouldn't it be a melancholy time for you?"

Harry shrugged a shoulder. "I think my parents would rather I be happy," he responded candidly.

Snape peered up at him, scrutinizing his expression. Then, he let out a huff. "Give me the bloody pail," he muttered, snatching it away from the teen. "But just one street, Potter! I won't have you dragging me all over muggle London just to collect sweets."

They started off down the street, Snape with his ghost pail and vampire costume and Harry clad in something that had been designated a 'space cowboy' – whatever that was. As they approached the first house a group of rowdy teenagers came down the walk and just about trampled them. Or at least, that's what it must have seemed like to Snape, for Harry looked down to find his hand tightly gripped by a smaller one.

"Not a word to anyone, Potter," Snape growled. "Or I'll put a depilation draught in your morning tea."

Harry gave a small smile, gently giving the little hand a reassuring squeeze. "Not a one, Severus," he answered easily.

Dark eyes rose to meet his, again, gauging his sincerity. The Potions Master clung to his hand a moment longer before almost reluctantly letting go. They tread up the walk and after a put-upon sigh, Snape reached out to ring the doorbell.

"Still a dunderheaded idea," he grumbled, but Harry couldn't help but notice the glint of childish delight that shone in his eyes as a treat was dropped into his bucket.