The air grew colder with every passing second.
Rain had turned to mist, and mist to frost. Ice crept along the windows of the Hogwarts Express, turning each pane into a trembling mirror of white. Inside the train, students began to huddle together, their breath fogging, their chatter vanishing into silence.
Cael felt the shift instantly—the drop in temperature, the sudden dread crawling up his spine. He stood, wand in hand, and slipped out of his compartment. His boots echoed softly in the narrow corridor as he moved toward the front of the train.
And then—he saw it.
The train door creaked open.
Two tall, hooded figures glided through the mist into the corridor. Dementors.
Their rotting hands brushed the walls as they moved, and every step made the train grow quieter, colder. Students screamed from behind doors, others whimpered or sobbed. The Dementors, undeterred, drifted forward.
Cael didn't hesitate.
He stepped into the corridor, pointed his wand straight at the nearest figure, and shouted, "Expecto Patronum!"
A swirl of silver mist burst from the tip of his wand—and solidified into a small silver cat, elegant and quick, its tail twitching like a whip.
The Patronus hissed and leapt.
The first Dementor recoiled as the silver feline lunged toward it. The moment the Dementor tried to brush the animal away, the Patronus bit. A vicious snap to the neck—and a hideous screech echoed through the corridor as the Dementor retreated in a blur of robes and darkness.
Cael spun and saw the second one slinking toward another compartment door.
"Expecto Patronum!" he cried again.
The silver cat darted through the air, pounced on the second Dementor's arm, and sank its fangs into its shadowy limb. With another screech, that Dementor was driven away too.
Cael locked the front doors with a quick sealing charm, then moved swiftly down the train. Outside the window, dozens more Dementors swirled in the fog—tall shadows circling the carriages like wolves around wounded prey.
He reinforced the seals at every entrance.
Inside, students were crying, shivering, clinging to one another. Prefects scrambled through the corridors, checking compartments. Even Percy Weasley, pale and visibly shaking, was trying his best to appear in control.
"Everybody stay calm!" he declared, voice cracking.
Fred and George emerged from their compartment too, wands drawn. "What the bloody hell is going on?" Fred asked.
"Dementors," Cael said grimly. "Lots of them."
"Are you serious?" George paled.
"No. They are." Cael pointed to the shapes outside the window. "Stay alert. Protect the first-years."
Further down the train, Ginny and Neville were being ushered forward by the twins. Ginny looked shaken, eyes wide with fear. Neville was ghostly pale, but determined.
Cael continued forward until he reached a familiar compartment.
Inside sat Ron, Hermione, and—Harry. The boy looked pale, but not unconscious as Cael had feared. He was breathing fast, gripping the seat tightly. Beside him sat a girl Cael didn't recognize. And across from them, slumped awkwardly in his seat, was Professor Remus Lupin, apparently fast asleep.
Odd. The entire train was chaos—and the new Defense Against the Dark Arts professor hadn't stirred.
Before Cael could speak, a prefect called down the corridor.
"Who cast the Patronus?"
"I did," Cael replied, raising his hand.
The prefect hesitated, then nodded in approval. "Good work. You drove them off."
Percy approached next, still trying to carry himself with authority. "Cael," he said, swallowing nervously, "thank you for—"
"You're not going to punish me for spellcasting?" Cael interrupted, one brow raised.
Percy shook his head. "Not this time. You saved people."
Cael blinked in surprise, then nodded. "You're welcome."
Suddenly—BOOM!
The door to the train blasted open with a violent gust of wind and mist. Everyone turned.
Three Aurors stood in the entrance—one older man with a cruel sneer, flanked by two younger agents. The senior Auror stepped forward, shouting above the noise.
"Who cast the Patronus Charm? Who interfered with Ministry operations? Step forward, now!"
Cael stepped ahead of the prefects without hesitation. "I did."
The Auror narrowed his eyes. "You dare attack Ministry-assigned Dementors? That's a criminal offense!"
"They were inside the train," Cael said coldly. "They were attacking students."
"They were searching for Sirius Black," the Auror snapped. "A fugitive. Nothing more."
"Searching?" Cael scoffed. "You call draining the happiness out of children searching?"
He turned to Percy. "Send an owl to Professor McGonagall. Now."
Percy faltered—then nodded and rushed off to find a school owl.
"Enough!" barked the Auror. "You've interfered with a sanctioned security operation. Arrest this boy!"
The younger Aurors stepped forward.
Cael raised his wand.
"I dare you," he said softly. "Arrest me. Attack me. I'll fight back."
"Cael—" Fred and George appeared at his sides, wands drawn.
Lee Jordan joined them, then Ginny, wand trembling in her hand. Even Neville stepped forward, eyes determined, wand clenched in his fist. One by one, the prefects and Head Girl Penelope Clearwater stepped out, raising their wands in quiet defiance.
"You can't take a student without Dumbledore's permission," Penelope said firmly. "You'll have to hex us all first."
The Auror sneered. "A pack of children playing heroes…"
He reached for his wand—
"That's enough."
Everyone froze.
From the shadows of the corridor emerged a tall, pale man in worn robes. He looked tired—no, exhausted, as if he hadn't slept in days—but his presence silenced the entire train.
"I am Remus Lupin," he said. "Defense Against the Dark Arts Professor. Appointed by Albus Dumbledore himself. And you, sir, have no authority to take any student from this train."
"Who are you to—?"
"I've already informed the Headmaster," Lupin interrupted coolly. "He's speaking with the Minister of Magic as we speak. You have jeopardized student safety. Your Dementors terrified them. Some nearly fainted. If you had let them go one minute longer, they could have kissed someone."
The Auror clenched his jaw, backing down slightly.
"The train is behind schedule," Lupin continued. "Because of you. So either step off, or I will have every Prefect here record a formal complaint to the Ministry."
The senior Auror spat at the floor. "This isn't over. You're breeding rebellion in your students."
"No," Lupin replied calmly. "I'm teaching them how to stand up to injustice."
With one last glare, the Aurors turned and stormed off the train.
The moment they vanished, the tension snapped.
"Brilliant," George whispered. "Bloody brilliant."
"I thought he was asleep!" Fred added. "What an entrance."
Lupin turned back toward the students. "Well done," he said simply. "Every one of you. But next time, don't challenge Aurors to duels unless you've already passed your NEWTs."
A few nervous chuckles followed.
"Now," Lupin said, "back to your compartments. Prefects—do a full check for injuries. I'll speak to the conductor."
As students returned to their places, Cael followed the twins back into their carriage.
Ginny and Neville slipped away to find Harry. Hermione rushed to make sure everyone was alright.
Fred clapped Cael on the back. "Mate, you stood down an Auror like he was a first-year who stole your lunch."
George whistled. "He deserved it. Letting Dementors onto the train? What kind of mad operation is that?"
Cael sat by the window, looking out. The Dementors were slowly retreating, gliding away into the mist, though many still followed the train from a distance.
He exhaled. "Let's just hope this doesn't escalate any further."
Outside, the mist thinned.
And slowly, the Hogwarts Express began to move again.