I'm so sorry this Chapter is late. I've been very busy preparing for the end of term, and haven't sat at the back of class regularly to write secretly (I'm so sneaky ;) ). Anyways hopefully worth the wait…

Aziraphale ducked and dodged through the corridors to Lupin's office. The preparations for Christmas were making the commute from place to place harder than ever, which was saying something as the moving staircases, disappearing doors and general presence of Peeves made it very difficult as it was. Aziraphale was intercepted by no less than three suits of armour asking him to judge their rendition of 'Silent Night' as well as being attacked by a flock of Flitwick's live fairies, in a mood because one of the portraits had laughed at their hair (fairies could be quite viscous when roused). All in all, it took him fifteen minutes to get to Lupin's office, where he found Crowley waiting.

"Sorry," he said, coming into the classroom, it felt wonderfully warm after the chilly corridors as several logs were glowing in the cavernous fireplace, "corridors were a nightmare. Did I miss anything?"

"No," Crowley leaned back against the desk, "I've been going out nightly and haven't seen the dog again. I even asked Hagrid to look out for it, said I had met the owner in Hogsmeade."

They had agreed that it would be too risky to just leave a note for the dog, as anyone could find it, including (and they were all trying not to think about this) the dementors.

"And I still have no idea why he attacked Peter," Lupin massaged his temples with his hands. The full moon had been last week, and he still looked tired, "it's the only thing that contradicts his innocence. Apart from James and Lily of course, though I'm certain he didn't betray them under his own steam at least."

"We need to find him," Crowley said, still frowning hard, "It's the only way to find out the truth."

"I want to talk to him to," Lupin stared at his desk, "to apologise. I should have done more to prove he was innocent."

"To be fair," Crowley said, "you thought he had killed twelve people and betrayed your best friend. And we still can't prove he didn't'."

"But it doesn't make any sense, and I should have seen that," Lupin muttered.

Aziraphale sighed. He didn't know what to say. At least Harry was safe. Probably.

"Well," he said brightly, "Crowley and I are on duty in Hogsmeade this weekend, we'll ask the locals then."

Lupin looked slightly happier.

"And Harry is safe, probably," Aziraphale said.

"But Black did come to Hogwarts, where Harry is," Crowley looked grave, "we still don't know why he's here either."

"He might genuinely want to see Harry," Lupin said quietly, "you see, he's Harry's godfather."

"His godfather?" Aziraphale asked.

"Sirius was James' best friend, so he was Harry's godfather, yes," Lupin explained, "I'm sorry I didn't mention it sooner, I forgot if I'm honest."

"Maybe we could try and find someone in Hogsmeade who could deliver a letter to him for us," Aziraphale suggested.

"I'm not sure," Crowley said, "we would have to tell that person at least part of what's going on, and I'm not sure it's a good idea to trust someone too quickly. Also, I doubt anyone else will have any luck finding the dog, if we can't."

Aziraphale sighed, "we'll just ask who has seen it in Hogsmeade, and maybe something else will come up."

They talked some more, then the bell rang out in the corridor.

"Well, I have a class," Crowley said, and left the room.

…

He had reached the Defence Against the Dark Arts classroom when he heard someone calling to him.

"Excuse me Professor."

He looked round. It was Harry. Crowley had hardly seen him since the Quidditch match and was relieved to see him looking a lot better. He had taken Gryffindor's defeat hard, as well as the loss of his broomstick, and Crowley had honestly been a bit worried about him.

"Hi," Crowley invited Harry into his classroom. He still had time before the lesson.

"I wanted to ask you something," Harry said, as Crowley closed the classroom door.

"Okay." Crowley felt slightly nervous.

"I saw the dog again, during the Quidditch match," Harry started, "before…before the dementors came."

"I still don't think it's a Grimm," Crowley said quickly.

"Whatever it is, I think it's interested in me," Harry said earnestly, "I think it followed me from my aunt and uncles house."

Crowley wanted to tell Harry not to worry. That it was in all likelihood his godfather coming to watch his Quidditch match. But he also didn't want too many people knowing what they were up to. Harry would tell Ron and Hermione, who could tell other people, who could tell other people. There was also the small fact that most of what he and Aziraphale suspected were just that, suspicions, with no proof. Yet. But he had to tell Harry something. So, he told him as much of the truth as he could manage.

"I'm looking into it, Potter. But I don't have anything concrete yet. It might be interested in you, but I doubt it's trying to hurt you. Just…don't worry."

"You'll tell me though, if you find anything?"

"Yes."

He would. If Black was innocent, and they could prove it, he would. Harry deserved to know the truth.

Harry thanked him and walked to the door, but he hesitated before opening it, looking back.

"Can I ask you something else Professor?"

"Yes." Crowley felt nervous again.

Harry fiddled with the sleeve of his robe. He looked even more awkward than Crowley felt.

"Do you think, maybe, you could teach me how to fight dementors? It's just, if they come to another Quidditch match and…I don't want to let the team down again. I don't know why they affect me like that."

"Because you have bad memories Potter," Crowley found himself saying, "you're more…vulnerable to them, the worse stuff you've experienced."

He remembered how in hell, they had rarely sent children down to the demons, because they couldn't get the same effect. He blocked out the memories quickly, trying not to think about the people they had sent to see them.

Harry considered.

"Is there a way to fight them then?" he asked finally.

Crowley sighed.

"There is, but I can't teach it to you."

"I'm not scared or anything, I'll face them," Harry's eyes burned in a way that made Crowley want to smile. But he didn't, because he didn't want Harry to think he wasn't taking him seriously. And also, because he was about to admit something tricky. He took a deep breath.

"I can't cast a Patronus Potter," he said.

Harry must have seen the shame in his face, as he didn't even ask what a Patronus was. He glanced at the door, clearly considering his exit.

"You could ask Professor Fell though," Crowley added quickly, "he can cast one."

Harry nodded slightly awkwardly, "thank you."

He was replaced, as he left the classroom, with the fifth-year class Crowley was to teach. Crowley started the lesson as ever, but his heart was leaden in his chest.

…

He asked Aziraphale about anti-dementor lessons for Harry when they switched so he could take the next class, but to his surprise, Aziraphale said he needed to think about it, and would say no more. He looked pensive. Crowley had expected him to jump at the opportunity, but maybe the angel didn't want to teach him such advanced magic. Crowley thought that Aziraphale underestimated Harry sometimes.

…

According to Aziraphale, a north wind was due to bring snow down to Hogwarts, on the day of the Hogsmeade visit and sure enough, the grounds were obscured beneath thick white drifts when Crowley looked out of the window that morning. He scowled. Crowley hated cold weather.

After breakfast, they walked down the Hogwarts drive toward the village, grateful that they didn't have to endure Filch, like the students. The walk was cold, with the last flakes of snow still floating down around them, but the beautiful view of the castle transformed into something out of a fairy-tale made up for that. Hogsmeade too looked stunning under its coating of snow, packed with shoppers preparing for Christmas.

"Well," Aziraphale looked about them, "where to first?"

"We should split up," Crowley said, "cover the ground faster. I'll take the Post Office," he added, pointing to a red blue sign, decorated with owls above a shop, bustling with witches and wizards sending Christmas cards and gifts.

"Good idea," Aziraphale scanned the busy street, "I'll take Honeydukes."

Crowley raised an eyebrow.

What? It's very popular, there will be lots of people there," he protested.

Crowley just shook his head, grinning.

They split up. Crowley squeezed into the Post Office, grateful for the warmth. The hooting of owls and the chatter of shoppers filled the air. He quickly approached the front desk. He and Aziraphale had worked out what they were going to say on the way down, so Crowley just had to ask as many people as possible.

"Hello," he said.

The wizard behind the desk smiled warmly.

"Merry Christmas," he said, "Parcel or letter?"

"Neither," Crowley replied, "I've come to ask if you've seen a dog. It belonged to one of the teachers up at the school, and it's missing."

"Not Fang? Hagrid's dog?" The wizard asked, looking concerned.

"No, but it's about the same size. And black."

"You know, I think I might know which one you mean," the wizard looked thoughtful, "how long's it been missing?"

Crowley thought on his feet. If Black had been hanging around the village, he had probably been doing so since the beginning of term.

"Start of term," he said finally.

"Got scared by all the students coming back huh?" the wizard laughed.

"Something like that."

"I think I might have seen him."

"Really? Where?"

"Around the outskirts of the village," the wizard replied, "honestly, there's not much bother trying to get him back if it's the same dog I've been seeing. I think it's gone wild. Friendly enough though."

"Thanks," Crowley said, and slipped back out into the cold.

…

They wandered the village for about an hour, asking various witches and wizards if they had seen the black dog, before meeting in the Three Broomsticks (Hagrid had recommended it to them) to review their progress.

"Well, it sounds like he's been hanging around here," Crowley told Aziraphale, "from the sounds of it, he's been living somewhere in the outskirts of the village and coming in to scrounge for food. A couple of people have been leaving out leftovers for him. He's quite popular."

"I feel sorry for him," Aziraphale said, stirring his butterbeer in a melancholic manner, "it sounds like he's been living off scraps for months."

"Did anyone suggest where he might be sleeping?" Crowley asked.

"Nobody," Aziraphale slumped a little in his seat. He a had clearly been hoping to ask Crowley the same question, "did you meet anyone who might be trusted to pass on a note to him?"

"No," Crowley sighed, and sipped his fire whisky.

They sat in silence for nearly five minutes before Aziraphale spoke again.

"I did see something strange though."

"What?" Crowley was hoping for news of Black, so Aziraphale's answer disappointed him.

"I could have sworn I saw Harry in Honeydukes."

"You probably just imagined it," Crowley said, thinking that if Harry really had found a way to go to Hogsmeade then he deserved to have a good time. he changed the subject quickly, "What about those dementor lessons then?"

"I have been thinking about that," Aziraphale replied, "and I think I'm going to ask Lupin to teach him."

"What?"

"He deserves to spend time with him. Harry is his best friend's son. Probably the closest thing to family that Lupin has."

Despite the disappointment of the day, Crowley smiled. Sometimes he forgot exactly why Aziraphale was an angel.