The Hagrid's son

Gunter's igloo was a complete success among the students, many of whom lamented that it would melt away in time. But sometimes, the best moments are precious because they're fleeting.

Barnaby received a request from Professor Sprout to help prune the Whomping Willow and check on its health. However, since he was tied up during the day—having even postponed the task due to Ginny, who had nearly mastered the Patronus Charm—he approached the imposing tree late at night as his final task of the day.

It wouldn't take long anyway.

He arrived just in time to see a large black dog running out from Hogwarts Castle, stopping a few meters from him, uncertain how to react, cautious of his presence.

Barnaby paid attention, not only because he was certain Fang didn't have a brother or because the dog had emerged from the castle at such a late hour, but because the dog approached the Whomping Willow voluntarily.

No animal with instincts and any semblance of intelligence does that, except for a few clueless birds.

Sirius Black's POV

"Damn it! I wasn't expecting to run into Hagrid's kid right now," Sirius thought, while in his Animagus form, trying not to give away his true identity.

The worst part was that he was right in the middle of the hidden path between the Whomping Willow's roots and didn't have much time. That Weasley had to ruin everything when he was so close to catching the rat!

The castle would be on alert in just a few minutes…

"I'm faster in this form, and I don't see him carrying a wand. I can scare him and run off while he's frightened," Sirius calculated anxiously. "Though this risks revealing the passage, I have no other choice. I just don't have time for anything else!"

"Sanshi."

"Huh?" Sirius was confused. "I think I remember the dog was called Fang…"

But it didn't seem like he had been mistaken for that dog.

So, who was Sanshi?

The creature that emerged from the boy's shadow suddenly nearly gave Sirius a heart attack, leaving him momentarily paralyzed and giving the entity enough time to assault him with a flurry of blows that knocked him out cold.

Third Person POV

Sanshi finished punching, kicking, and clawing at the black dog and then grabbed him by one of his hind legs, hanging him upside down like a chicken.

"I think he's not very healthy—all I felt was skin and bones," Sanshi commented as she held the dog away a bit due to the bad smell.

When was the last time this guy had a bath?

"It's strange to see an unknown Animagus able to enter the castle like this," Barnaby said as he examined the intruder from head to toe.

Had Sanshi hit him too hard?

In theory, if he was unconscious, the transformation should have ended…

"Ugh, the Animagus form never interested me, and I really don't know as much as Aunt Minerva. I barely managed to learn how to identify Animagi," Barnaby sighed, rubbing his forehead.

He liked being who he was, so why would he want to learn to be something else?

"Should we wait until morning?" Sanshi asked as she looked at the unconscious Animagus. "Everyone must be asleep at this hour, and this guy won't wake up anytime soon. I can stay up, keep watch, and knock him out again if necessary."

"Hmm, no, I think it's better to deal with this as soon as possible," Barnaby shook his head.

Although he was tempted by the proposal because he was quite tired and wanted to go to sleep, postponing things like this always ended up causing some sort of problem.

He sent a house-elf to notify the Transfiguration teacher and met her in the Great Hall, which was currently empty, with only the tables and house point counters present.

"Barnaby, what's this about you catching a…?" McGonagall entered anxiously, but she couldn't finish the question when she saw Sanshi holding a black dog upside down.

Barnaby realized now that in his haste, he had forgotten to hide Sanshi, but he had to deal with the situation and try to solve everything before it spiraled out of control.

"Aunt Minerva, this is Sanshi, my familiar," he explained briefly. "I'd appreciate it if you didn't tell anyone about her for now. I think you understand the reasons."

"Hello," Sanshi greeted cheerfully.

"…Very well, I assure you no one will hear about her from me," Minerva promised, shaking her head to refocus on the matter at hand. "But the intruder…"

"He's the black dog she's holding—an Animagus I caught near the Whomping Willow," Barnaby explained what had happened with the relevant details while Sanshi laid the unconscious dog on the floor and retreated into the shadows. "The thing is, he should have reverted to his human form by now, but as you can see, something's off."

Minerva frowned, her sharp eyes fixated on the black dog as she cast a spell to undo the Animagus transformation.

"It's him!" Minerva almost jumped when she saw Sirius Black lying on the floor, still unconscious.

Barnaby had caught the fugitive Sirius Black!

"I need to wake the headmaster!" Minerva sent a Patronus to fetch the school's headmaster. "You've done an excellent job, Barnaby."

Minerva didn't know that the headmaster was already awake, having been alerted by the portraits that Sirius had entered Hogwarts, and was busy activating several hidden defenses around the castle!

"It's nothing, Aunt Minerva," Barnaby waved off the praise, though he was secretly surprised that the dog turned out to be Sirius Black. If he had known, he would've sent him to Tonks with a ribbon around his neck. "I think two Animagi in the school are enough."

"Quite right, two is plenty…" Minerva nodded but then paused, realizing she might have misheard. "Barnaby, did you say two Animagi?"

He wasn't referring to Black right now, was he?

"Yeah?" Barnaby was now the one puzzled by the question, replying a bit uncertainly. "You know, you and the Weasleys' rat?"

The look of astonishment on McGonagall's face was unparalleled in all of Britain.

"Barnaby, how long have you known?" Minerva asked, taking a deep breath to calm herself and try to make sense of the situation.

"Since he arrived with Percy at the school…" Barnaby was growing more confused by the questions. "I thought all the professors knew but pretended not to, that the Weasleys had brought a hidden bodyguard to Hogwarts."

"Bodyguard?!" Minerva inquired, unable to follow Barnaby's logic.

"You know how pure-blood families feel about the Weasleys, so I figured they put someone in place to protect their kids even at school!" The redhead explained what he thought was a well-known fact for years. "It seemed strange when he arrived with Percy and no one said anything, but then he passed on to the twins, and later to Ron. I assumed in a couple of years, Ginny would be the one under this bodyguard's watch…"

Minerva pressed her lips together, realizing Barnaby had misunderstood the situation completely. He had overestimated everyone's sensitivity to magical creatures, thinking they could easily recognize an Animagus at a glance.

Then, his observations and assumptions had given birth to a completely crazy theory…

"By Merlin's beard," Minerva sent another message to Dumbledore, urging him to take action against this stowaway who had been under their noses for years, now that Sirius had been neutralized.

An hour later, several professors and Barnaby stared in shock in the headmaster's office at the two figures lying on the floor, both now in their human forms.

"Wasn't Peter Pettigrew supposed to be dead?" Barnaby couldn't resist asking.

"It seems the situation is more complicated than we thought," Flitwick commented on behalf of everyone.

"By the way, where's Lupin?" Barnaby suddenly noticed that the Defense Against the Dark Arts teacher wasn't present.

Snape was glaring at the two on the floor, wishing certain dark thoughts upon both…

Dumbledore looked at the scene, knowing the repercussions of what had been uncovered tonight, and felt a headache brewing for the morning.

No, probably for the entire week!

He needed a lemon sherbet—no, make that two!