Lynn precisely copied the starlit patterns from the metal pages in the Restricted Section onto parchment, like a code woven from an ancient Star Chart and the veins of the earth. Hermione practically pressed her face to the drawing, her fingertip tracing a winding silver line. "Look here! This Energy Node marker perfectly matches the Ice Crystals trail we found in the Defense Classroom! It points to... an abandoned Magic Hub near the abandoned Girls' Lavatory on the second floor!"
"Moaning Myrtle's territory." Harry caught on immediately. "That's where the pipes are most densely packed!"
"And according to the Star Chart," Hermione said excitedly, pointing at another intersection heavily marked with starlight, "there's an ancient 'Diversion Valve' here. In theory, it can temporarily cut off or alter the flow of magical energy through specific pipes! If we can control it, we can set a trap along the Basilisk's route, or at least... seal off part of its territory!"
Ron leaned over, scratching his head at the mysterious lines. "Sounds great, but how do we find this 'valve'? Is it inside the walls?"
"The Star Chart says the entrance is..." Hermione's finger followed the pattern before finally stopping at one spot. "...beneath the stall where Moaning Myrtle is, behind a loose Inscribed Floor Tile?"
"In the girls' toilet?!" Ron shrieked, his face twisting into a knot. "Merlin's stinking socks! How are we supposed to get in? Wear the Invisibility Cloak and listen to Myrtle cry all night?"
"Maybe... we could ask her for help?" Hermione looked at Lynn, a mischievous gleam in her eyes.
Convincing Moaning Myrtle was far more "lively" than they had imagined. When Lynn calmly said that he wanted to look at "the floor tile beneath her stall with the pretty pattern," Myrtle froze for a moment