"We saw the open door and came down to investigate," Trelawney proclaimed as the four of them left the Great Hall. "Strange, a brief consultation with my crystal ball just half of an hour earlier revealed a shadowed figure returning to the place where the blood was spilled." She stared at Snape over the magnifying lenses of her glasses.

Snape looked back with undisguised loathing. "As always your craft fails you, Sybill, as does your memory. Smith was poisoned, not stabbed."

Trelawney huffed. "I was speaking figuratively, but you're always quick to misinterpret my words for the sake of insults, Severus."

"My dear friends, I believe we should put aside old animosities in times like this," Flitwick interjected as Snape opened his mouth for another scathing retort.

"If you want my opinion, I taught about the treacherous nature of Goblins and their progeny long enough to recognise the signs of it," Binns said in his reedy voice.

"Don't you worry, Cuthbert." Flitwick smiled sweetly. "I'm no danger to your life."

Binns jutted his chin and turned to float off.

"Resume your post, Cuthbert," Snape said. "And this time, don't let anyone in."

"I'm a member of the staff myself and deserve some respect," the ghost complained before returning to the doors. "I have more pressing things to do than playing guard the whole day."

'The staff meetings must be fun," Harry muttered as Snape went to notify the Headmistress of his findings, and Trelawney headed to her tower, both pointedly looking in different directions as they took the same staircase up.

Flitwick snickered. "Oh, they are. Those two do enjoy their dramatics." His smile dimmed. "Everyone is on edge with these horrible events, so their animosity may seem greater than it is."

Harry thought Flitwick was overly optimistic about their relationship, but then again, he was not aware of Trelawney's prophecy and the role it played in Snape's life. And if Harry knew anything about Snape, it was that the man held on to his grudges.

A mangy reddish-brown cat darted past their feet and towards the door opposite the Great Hall, which Harry remembered to be Filch's office. Before the feline crashed its head into the wood, a cat flap materialised, smoothly letting it in.

"Neat," Harry said. "A successor to Mrs. Norris?"

"Yes." Flitwick hid a small amused smile. "Minerva holds no more love for this one that she did the previous."

"Wait a minute." A thought came to Harry. "Does Filch live here as well?"

"Yes, his quarters are connected to his office." Flitwick looked at him quizzically.

"Maybe he had seen the poisoner?" Harry felt stupid not thinking about it earlier, seeing how many times he would bolt off with Ron and Hermione from Filch doing his midnight rounds.

"Old age has finally caught up on Argus, and our dedicated caretaker doesn't leave his room as much anymore. But maybe he did hear something. He always complains about his troubles with sleep."

"It's worth checking out."

"You do that, my boy. I'll be in the staffroom if you need me."

"You think he'll talk to me?"

"I don't see why not."

Moving to knock on the door, Harry was pretty sure he heard heavy steps walking away from it on the other side. Harry waited for a couple of moments before raising his hand to the dark wood. The plaque saying 'Caretaker's Office' had a crude word written over it, only half-scrubbed off. In his days, Filch would make whoever responsible—or any unlucky student who happened to be in the vicinity when Filch saw it—clean and polish the plaque until it shined like a Quidditch Cup, but now it was darkened with dirt around the edges.

The footsteps came back, louder this time. The door opened a sliver, and Filch's head peeked out. His grey hair, as always thin and unkempt, had receded even more, leaving a bald spot. With its discoloured patches and surrounding greasy hair, it also looked to be in dire need of a wash and polish.

"Can I talk to you, Mr. Filch?" Harry asked.

Rheumy eyes blinked at him in distrust, but the door opened wider.

"Come in, then. Not many people come to talk with old Filch these days."

Leaving Harry to follow and close the door behind him, Filch limped to the depth of his office, leaning heavily on his cane. The space was cluttered with cleaning supplies and confiscated items. It was better stocked on Fanged Frisbees than the Weasleys' Wizard Wheezes itself, and the Skiving Snackboxes, stacked in a careless tower that needed only a sneeze to topple on their heads, came in a close second.

There was only one window under the ceiling. Long and narrow, it did not provide much light. Instead, an oil lamp sat precariously on the pile of parchments on the desk.

He picked up the lamp and motioned Harry to another room. "There's a fireplace in the sitting room. Dratted drafts and cold, and my legs aren't what they used to be."

The sitting room was similarly modest and had the same window as the office. Recalling the outside layout of the circular building adjacent to the castle, Harry suspected that the bedroom was not much better. He was beginning to understand why Filch had preferred to prowl the halls instead of staying inside his quarters. The air was musty and stale. The smell of cats and old age permeated the room, bringing back childhood memories of Mrs. Figg's house.

With a heavy grunt, Filch lowered himself into an armchair with a moth-eaten tartan plaid thrown over it, and Harry sat in an equally old, but clearly much less used sofa. The cat jumped on Filch's lap, its yellow eyes regarding Harry distrustfully.

A black kettle hung on a hook in the fireplace—Harry remembered Hagrid having one like that, only three times as big.

"A cuppa would be nice now," Filch looked at the kettle meaningfully.

"Let me make it for you."

There were oversteeped leaves in a mismatched teapot and a dirty cup on a mantelpiece. Harry hit it with a Cleaning Charm.

Filch creased his bushy eyebrows at the casual display of magic where he would have to use a dripping sink in the corner but made no comment of it. "The other cups are in the cupboard over there," he said instead.

Harry found two cups covered with a layer of dust and took one that wasn't chipped. He made his best attempt at casting a wandless and non-verbal Scourgify on it as well.

"I don't often have guests here. It's just two of us, right, Dolores?" Filched cooed at the cat, petting her.

Harry, who was fumbling with a poker to get the kettle out of the fireplace, almost dropped it at the name. Dolores, who had just settled on Filch's lap, raised her head again, eyes glowing in the semi-darkness.

"Good woman, Madam Umbridge was. Whatever people said about her afterwards, she brought order and stability to Hogwarts."

Harry did not trust himself with words. Instead, he picked a sugar bowl with clumped-up walls. "Sugar?"

"Two spoonfuls. Shame she didn't see eye to eye with old Headmaster. I'm sure whatever bad blood was between them, it was a misunderstanding."

"You think so?"

"I should say so. Dumbledore was a great man, with a heart of gold. Gave this job to me, eh?"

"He gave all people a chance." There was a time Harry had believed that unreservedly.

"Too right. He did not always keep a firm enough hand on the miscreants—stretched too thin with all his important duties. But he always found time to send me a small Christmas tree with the start of the holidays." Filch looked accusingly at the tree-less corner. "New Headmistress doesn't have time for old Filch."

"I'm sure she just doesn't know about your tradition with the Headmaster." Harry gave him a steamy cup, noticing how Filch's hands shook slightly when he took it. He wondered how old Filch actually was. Way too old to be mopping the floors of the enormous castle.

"My dear late Mrs. Norris never liked her, and Dolores doesn't either," Filch said as if it sealed the deal. "Always too busy to listen to the lowly caretaker. All of them are. Only Professor Snape ever asks me how I am anymore. Sent me a jar of the joint ointment the other day."

As a child, Harry used to hate Filch, an annoying obstacle on his late night misadventures. Looking at him with adult eyes, he saw a desperately lonely, confused old man.

"But you didn't just come to talk about my ails, did you, Mr. Potter?" Filch slurped his tea.

Harry took a sip as well. "Actually, I wanted to ask you if you heard anyone this morning, from around five to six o'clock?"

"Oh yes, and what a busy time that was. I wanted to have another hour of sleep after a bad night, but was not to be."

"Really? Can you tell me what exactly you heard?"

Filch puffed his chest self-importantly. "First, as I was turning in my bed, somebody walked into the Great Hall, waking me completely."

"Could you tell if it was a man or a woman?"

"I wasn't with my ear to the door," Filch said with a huff. "It was hard to tell. But the steps were on a lighter side, so perhaps a woman."

Harry got his Healer notebook and made a note in it with an ever-sharp pencil, the bane of his quill traditionalist boss.

Filch looked appeased, reaching to the small table nearby to get a tin of ginger nuts and dunking one into his tea. "Then, after a while, there was another set of steps. Maybe those were male, but again, I'm not sure. There was a conversation—"

"A conversation?"

"I couldn't hear the words, but it sure was heated. One voice was definitely female, before you ask. And they left together."

Harry's mind whirled. So after the culprit had come into the Great Hall, another person had joined them. Were they in on it?

"After that," Filch continued, "Professor Smith came."

"How do you know it was him this time?"

A familiar, nasty expression appeared on Filch's wrinkled face. "He kicked poor Dolores, as he was wont to do. A piece of work that boy was. Professor, ha."

Harry nodded, agreeing with the sentiment.

"He also ran into the suit of armour and created a horrible racket. Then swore for two minutes straight and, I believe, kicked it as well. Probably drunk as a fiddler's bi—very drunk."

"Yes, we've suspected he'd been drinking before going down." Harry did not elaborate whom he had meant by 'we', but Filch did not seem to need it.

"He rambled in the Great Hall for a while, but I didn't hear anyone answer him. Then, the strangest thing happened." Filch paused.

"Yes?"

"A dozen minutes after he had finally shut up, there was a sound of someone rattling the front door, but no steps leading to or from it. Maybe it was just the wind. But I don't think so."

If one had been up to no good, Harry thought, the smart thing would be to silence their steps. "Did it open?"

"No." Filch shook his head. "Hogwarts has been my home almost all my life, and let me tell you, Mr. Potter. It's not just a building. The castle knows when to open its doors, and when to keep them shut."

"Hogwarts is a special place," Harry agreed. "Did anybody come after that?"

"Somebody came and went around half-past six, and in twenty minutes, all of you appeared, starting with that Quidditch player trying the door as well. Why is he strutting around when he isn't even on the staff, I beg to ask?"

This must have been David going from the dungeons to the Hospital Wing. Had he come straight up as he said he had, or had he peeked into the Great Hall, seen Smith and had told nobody? Harry made a note to talk to the boy later.

"You remember all the details remarkably well, Mr. Filch," he said.

With a grunt, Filch put his cup on the table and produced his own, frayed and grease-smeared notebook from his pocket. He wetted his fingers with saliva and found the right page. "Ha! Memory is slippery, so I log every detail that might be important for catching those miscreants. Every suspicious sound goes here. How do you think I was able to ever catch those ginger demon spawn twins, friends of yours?" He was bursting with pride.

Harry smiled at the mention of the Weasleys. He wondered if they had known about this little black book and ever stole it. He would need to ask George if the occasion arose; in the last few years, he could reminisce about their school adventures and mention Fred again without having a breakdown.

"Thank you for your help," Harry said, putting his own cup away.

"Good day, Mr. Potter. I remember you to be a delinquent, but I must say you seem to have outgrown your troubled youth."

With that shining endorsement, Harry finally left Filch's quarters. Unfiltered light of day, however bleak with the storm raging outside, had never seemed so welcoming. He leaned onto the window next to the front door and put his palm to the double pane painted over with esoteric symbols by the frost outside. Before talking to Filch, he had planned to go down and question the house-elves on the off-chance Snape's theory was wrong and the poison came from the kitchen. But it seemed the man was once again right, and the murderer—or was it murderers?—came to the Great Hall itself.

Who could it have been? Smith did not seem to be that well-liked, other than by Alicia, who, according to Professor Babbling, had her own motive. If Alicia was involved, was Oliver the second person? Harry shook his head. He didn't want to think the worst of his childhood friends. Both of them had helped Muggleborns in the year of Voldemort's reign and come to the DA's call to fight alongside him in the Battle of Hogwarts. Unlike Zacharias Smith, who had run away at the first opportunity, Harry's memory helpfully suggested.

As if in answer to Harry's thoughts, Oliver Wood himself stomped downstairs, looking like he had been dragged through a chimney. His face was smudged with dirt that went down his light-grey knitted jumper, and his hair was in disarray. Oliver tried the front door once again, but this time it did not even open a smidgen.

"Fuck!" he hit the door, but then immediately withdrew his hand, nursing it. His knuckles and his palm were scratched. "Fuck."

"What happened to you?" Harry asked cautiously.

"Tried to clear one of the blocked secret passages. One behind the one-eyed witch statue, you know it?"

"Yeah." Harry nodded. He had a lot of fond memories of that passage.

"Fred and George found it in their first year, who knows how. A trusty source of firewhiskey for the dorm parties, well, you know how it was."

Harry nodded, although he actually did not. Seamus used to smuggle booze into the school from who knew where, and they had gotten disgustingly drunk once in their sixth year after their first Quidditch match. Then being poisoned with Slughorn's mead had turned Ron off any alcohol for good until the end of the year, and Hermione would confiscate any drink stronger than butterbeer on sight. After that, there was the year on the run when they had kept themselves warm with cooking sherry that the previous owner of the tent had stocked up, but those gloomy evenings had little in common with any of the wild parties the upperclassmen would throw when Harry himself had been in his first years at Hogwarts.

"Did you clear it by hand?" he asked instead.

"There's an anti-spell barrier, but they did not count on good old manual labour!" Oliver crowed.

"So… any progress?"

His cheerful expression dimmed. "At this rate, I'll be done by Valentine's."

"I'm sure everybody knows about the storm by now and won't hold it against you."

"You don't understand, Harry. Professional Quidditch is not the Hogwarts Cup. You need to consistently prove your dedication and commitment to the team. Con-sis-ten-tly. And the last practice of the year? Quoting our coach, you get there even if You-Know-Who is out of his grave again, chasing you with a Beater's bat."

Harry stifled a wince at the casual use of Voldemort as a scare for lateness. "I remember all your motivational speeches when you were the Gryffindor Captain," he said. There was, however, such a thing as taking dedication too far. Or did Oliver have another reason for wanting to leave as soon as possible? No. Harry refused to succumb to paranoia.

"Those were the days. First steps of the big journey."

"Twelve steps, to be more precise," he said with a grin. Oliver had tried to introduce his twelve-step program at his last year at Hogwarts, complete with an animated presentation, charts and five a.m. practices in the mud and rain.

"And they paid off, didn't they? We only lost against the Puffs."

Harry shivered, remembering the Dementors and Cedric playing against him.

"And if Smith had beaten Diggory to the Seeker position, we'd have won that match even with you fainting."

"Smith tried for the position?" Harry had not kept up with the other team's tryouts, but he knew for a fact that Oliver never missed a chance to spy on their competition.

"Both in his second and third year. Probably continued later on, too. Useless on a broom. They say to never speak ill of the dead, but I can't bring myself to say anything good about his flying."

"Say, Oliver, did you come here earlier in the morning before we found Smith?"

Oliver's face closed off. "I first came down a couple of minutes before you appeared."

"That's what I thought. But maybe you've seen anybody when you—"

"No, nobody on my way from the Gryffindor Tower. I even thought that it was creepy to see the castle so empty."

"Gryffindor Tower? Oh, Alicia is the Head of the House now as well?"

"Yeah. So weird that it isn't McGonagall anymore." Oliver looked at his watch. "Well, it was great chatting to you, Harry, but I need to go. Those rocks won't roll themselves!"

"Good luck with that."

Oliver turned to go just as Snape appeared at the stairs. The two men shared a look of mutual suspicion.

"Is there a chance he'll be able to clear that secret passage by the stairs to the Defence classroom?" Harry asked quietly as Snape came down.

"Not the slightest," Snape said with a snort. "The Sysyphus Charm," he explained. "The rocks are spelled to refill when the passage is cleared halfway. Which I sincerely doubt this Quaffle-head will manage."

"Should we tell him?" Harry asked dubiously.

"Don't you dare, Potter."

"You might have a point." The passage would keep Oliver occupied lest he actually finds a way out and freezes to death under the storm.

"Why did you ask him if he was down here before? Did you think he would tell you if he had a detour to the Great Hall for an early protein-filled breakfast and a murder?"

Harry chuckled despite himself. As a student, he never noticed that Snape had a sense of humour, morbid as it was. "No, it's not that. There were apparently more people in the morning than Smith and whoever poisoned him."

"Oh?"

"I talked to Filch—" He cut himself off. Did he want to share this with Snape?

Snape's face lost all traces of his previous amused expression. "Of course. I didn't expect you to tell me anything."

Harry had a decision to make. It occurred to him that Snape shared something extremely personal with him earlier this day.

"I just didn't want to talk about it here," he said. "Let's go to the Hospital Wing, if it's all the same to you. It's time for me to check on Judith. We can discuss it there."

"Of course."

"And while we are at it, what was it about the goblet?" Harry asked, remembering Snape's expression from before.

"The goblet?"

"Yes. You definitely noticed something there."

"We established that the poison was on the edge. Do keep up, Potter."

Harry stopped. "No. There was something else, before. Don't take me for an idiot, Snape."

Snape gave him a brief, assessing look over his shoulder. "Where was Smith sitting when you found him?" he asked without slowing his steps.

Harry sped up to match his step again. "The same place he was yesterday."

"And the goblet? Did you notice anything different about it?"

"I didn't pay attention to his goblet yesterday,"—in fact, he had tried his best to ignore Smith as much as possible—"But aren't they all the same? Gilded silver, Hogwarts crest?"

"Unlike the staff goblets, the one that poisoned Smith was goblin-crafted. They might be of similar design, but saying they are the same is like saying that first-year's scales are the same as the customised self-calibrating set to measure stardust."

"So he wasn't supposed to have it?"

"No, he wasn't. The set is reserved for the Headmistress and important guests."

"So the poison was for Professor McGonagall? And Smith took her goblet?" This was something Harry could see Smith do.

"No, Minerva's goblet was untouched."

"But where did he get it, then? It's not like Hogwarts could expect any important guests in the morning while cut off with this snowstorm."

Now it was Snape's turn to stop and give him a look reminiscent of his student days when Harry would make a particularly poor attempt at a potion.

"What?"

"Are you really this dense?"

Harry looked at him in confusion before understanding dawned. "Oh. You mean he took mine."