On Tuesday morning, Catherine understood exactly what Sirius had meant by playing 'dirty'. The Gryffindor team had practice before breakfast and arrived at the Great Hall hungry but in high spirits. The third-years had a double Transfiguration class before lunch. As they headed towards the first floor, screams erupted from the Entrance Hall. From her vantage point on the top landing of the Grand Staircase, Catherine cast a curious glance below and saw Bella and Cissy Black drenched in mud, which dripped into puddles from their hair and clothes.
A barrage of what appeared to be mudballs flew through the open oak door, striking the two Slytherin girls hard and eliciting more screams. Bellatrix drew her wand but seemed clueless about the source of the attack and how to counter it.
"What did you do?" – Catherine whispered to Sirius, who stood next to her, a triumphant smile playing on his lips.
"I took inspiration from your snowball spell and tweaked the formula a bit!" – he sneered with satisfaction – "They always act so terrified of getting dirty and strive to preserve their purity. I thought it was high time to show them there's nothing frightening about a bit of mud. Consider it therapy!"
The young witch somehow doubted Sirius' cousins would interpret this attack in such a positive light. Yet, she couldn't help but be impressed by how skilfully her friend had devised and executed the plan. He must have enchanted the mudballs before coming to breakfast. Naturally, they couldn't have entered the castle unless someone opened the door, providing Sirius with a perfect alibi, since he was with all his classmates when the mudballs began mercilessly pelting the Black sisters.
While Sirius believed he had the upper hand and that his "warning" would deter Bella and Cissy from escalating their conflict, Wednesday's Care of Magical Creatures class proved him wrong. The Gryffindors and Hufflepuffs were revising how to care for Flobberworms when a sudden, dangerous incident occurred. The pen door of the enclosure housing the Hippogriffs burst open, and a loud noise sent the creatures stampeding from their quarters. Sirius, standing near the fence, threw himself to the ground to dodge the charging beasts and was trampled, sustaining kicks from several hooves. James and a few other students were also slightly injured, ensuring a busy afternoon for Madame Pomfrey.
"I think we all know this was not an accident." – Sirius declared angrily that evening, as they were all seated in their favourite spot in the Common Room. The young wizard had no injuries left but due to the big number of spells that had to be applied to mend his skin and a few bones, he was having a terrible itchy rash, which was driving him insane – "I can't wait for the Quidditch final to be over! While I don't shy away from putting Slytherins in their place it's exhausting always having to watch your back!"
"Do you really think today's chaos was just about Quidditch rivalry?" – asked Catherine flatly. She, herself, was able to avoid any harm by swiftly climbing a nearby birch tree to escape the agitated Hippogriffs.
"Of course! What else could it be?" – scoffed Sirius sarcastically.
"Um…Sirius…" – Peter interjected reluctantly – "I think I've seen something that I don't know how to tell you!"
"Just spit it out!" – snapped the young wizard, frustrated by his friend's hesitance.
"While the Hippogriffs were rampaging and Professor Kettleburn was trying to calm them, I saw someone sneaking back towards the castle."
"You did?" – asked Sirius, surprised – "Who was it?"
"Your brother." – the chubby blond boy admitted reluctantly.
"Regulus?! That bloody knobhead!" – yelled the grey-eyed teenager as he slammed his fist on the table – "So they think they can outsmart me! Alright then! The game is on!"
"Sirius, maybe that's enough?" – Catherine suggested cautiously – "This is getting out of hand pretty quickly!"
"It's just the beginning!" – sneered the young wizard, leaping to his feet – "I know you don't understand me but when you come from a messed-up family like mine, leaves no room for showing weakness—or you're finished."
Catherine let out a heavy sigh and also stood up. She rested her head on Sirius' shoulder and gently slipped her hand into his, prompting him to look at her with surprise. "Just be careful, okay?" – she whispered."
"I promise!" – he smiled affectionately at the young witch.
Unfortunately, that promise proved hollow. Sirius, seemingly spurred by Catherine's recent confrontation with Snape, abandoned the subtlety of spells as he strode decisively to the Slytherin table the following day and landed several solid punches on Regulus Black before Slytherins and alarmed teachers intervened.
This brazen approach yielded the desired effect of humiliation, provoking a swift and brutal retaliation aimed at inflicting maximum pain on Sirius. On Friday, Catherine Plantier missed her Defence Against the Dark Arts class after Bellatrix Black cast a Leg-Locker Curse on her while she ascended a staircase, causing a heavy fall accompanied by the panicked cries of her friends who failed to catch her in time.
Hours later, with a mended wrist and a plate of eclairs, Catherine sat in the near-empty Common Room, nestled beside Remus as they gazed at the stars through the window.
"I have a bad feeling about tomorrow, Moony." – she murmured drowsily.
"So do I." – Lupin replied with a furrowed brow – "Sirius wore this very determined expression which I don't like one bit. It always leads to a disaster."
"I warned him, didn't I?" – the girl lamented, stifling a yawn – "His life would have been so much easier if he listened to me more often."
"Perhaps that applied to all of us." – Remus mused, a playful smile tugging at his lips – "But you know how he becomes when it involves his family. Rationality gives way to emotion and old wounds."
"You're right." – the witch conceded thoughtfully – "And I can relate. Let's just hope maintain composure until the end of the match."