Inside the Room of Requirement, Erwin and Charlotte stood on opposite sides of the training arena.
"Go all out, Charlotte! Don't hold back!" Erwin commanded.
Charlotte nodded, her wand snapping into her hand. A crimson curse shot toward Erwin, but he merely raised a hand, casually deflecting it.
"Not bad. Fast execution, but lacking penetrating power," Erwin noted analytically.
Charlotte wasn't surprised. She knew her master's capabilities intimately. Remembering his instructions, she pressed the attack. Another spell hurtled toward him. Erwin vanished just before impact, leaving the curse to gouge a crater into the floor—a crater that sealed itself shut instantly.
Erwin reappeared directly behind her, tapping the back of her head with a single finger.
"Never let your guard down. Again!"
He flashed away, reestablishing distance. Charlotte swung her wand, and this time, a flash of sickly green light erupted—the Killing Curse.
Erwin flicked his finger. A piece of wood shot up, morphing into a massive boulder mid-air. It blocked the curse and obscured his movements. Charlotte immediately Apparated away, wary of a counterattack.
She reappeared across the chamber, scanning for him. Erwin's finger tapped the back of her neck again.
"Apparition is swift, Charlotte, but it leaves a magical signature," Erwin's voice cut through the silence. "Until you can completely mask every fluctuation of magic, you're visible to a skilled opponent. I restricted your Apparition privileges for this session for a reason."
Charlotte frowned. "I don't understand, sir."
Erwin withdrew his hand and appeared face-to-face with her. "Your reliance on it has become a weakness. If you used it now against Sunny Finch, she would exploit it immediately. She hasn't tested the specific counter yet, but she's already sensing where you'll materialize."
Charlotte's eyes widened. "I thought she was simply predicting my tactical patterns. I even trained to randomize my repositioning."
"Finch possesses the strongest combat instincts I've ever encountered," Erwin explained. "Her grasp of minute details is unmatched. You lack that innate intuition, Charlotte, but you can sharpen it through experience. Your magical reserves are adequate with the enhancement crystals I provided. Now, you must refine your tactical acumen and situational awareness."
Charlotte bowed her head respectfully. "I understand."
Erwin stretched. "Good. It's getting late. Hopefully, the others have concluded their... festivities."
Charlotte smirked knowingly. "I suspect you'll be sleeping elsewhere tonight, sir."
Erwin woke up in his office atop Cavendish Tower the next morning. Charlotte had been correct.
The girls had returned to their quarters in high spirits, making sleep impossible in the dormitory. Frustrated, Erwin had Apparated back to the tower to rest on his office sofa.
He was just rubbing the sleep from his eyes when a knock sounded at the door.
"Enter," Erwin waved his hand, and the door drifted open.
Old Tom stood in the doorway, holding a tray with milk and bread. Behind him, a small black dog—Ebony—wagged its tail enthusiastically.
"Breakfast, Master," Old Tom said, setting the tray down.
Erwin nodded, nudging the creature with his foot affectionately. "Old Tom, what's the status of the preparations?"
Old Tom straightened. "Everything is ready, Master."
"And the Demos family?" Erwin asked, picking up a slice of toast.
"No movement whatsoever," Old Tom replied. "Neither the Demos family nor anyone else in the American magical community has made a sound. Even our embedded contacts there are unable to gather intelligence."