She cast the most complex brain scan spells she knew and studied them.
“It didn't reach her brain,” she gasped with relief. Then she cast another diagnostic over Ginny's head. The ragged, hurried cuts made it hard to read any other details. She couldn't see any obvious indicators of remaining necrosis, but Hermione didn't trust Fate to be kind. She snatched Pomfrey's wand from her hand without asking, muttered a charm and began using the second wand tip delved into the diagnostic layers, looking for any remaining traces of rot hiding beneath all the tissue damage she was reading from the removal process.
There…
“There's necrosis in her zygomatic and frontal bones. I have to remove them now,” Hermione said. “Everyone get out!”
There was protesting which she ignored as she cast more blood staunching spells, trying to see exactly where the curse was still eating into Ginny.
“Give her one drop of Draught of Living Death,” she ordered Padma who had just poured blood replenishing potion down Ginny's throat. “It will slow the recovery but we can't risk her moving.”
Hermione grit her teeth and prayed as she summoned potions from the cabinet and began to cast a series of intricate spells and wards over Ginny's head. Many of which she had never used before or only used once.
Trying to remove any sections of the skull was horrendously risky in any situation, but far worse when trying to accomplish it rapidly. It was going to expose the sinuses, Ginny would lose her entire eye socket, and part of her frontal lobe would be exposed until the bones grew back.
Staring at the black spots on Ginny's exposed skull that were now growing before her eyes Hermione cast a hair removal charm and then spread a thick, purple potion very carefully around the edges of the gash and then out across more than half of Ginny's head and face. When it was carefully and evenly spread Hermione cast a setting charm. The potion grew hard and shell-like. An exoskeleton.
Hermione took a steadying breath and banished each section of Ginny's skull.
The exoskeleton potion externally held the areas which no longer had bone structure supporting them. Hermione recast the diagnostic and checked repeatedly and thoroughly. The necrosis was gone. The bones had been removed before the curse reached through to Ginny's brain.
Hermione collapsed slightly and felt tempted to sob with relief. It had been so close. So very close. Closer than she would ever tell anyone.
She steadied her hands and administered Skele-Gro. She added several monitor wards and several more protective wards around Ginny's exposed brain. Then she set a timer.
With the interference of Draught of Living Death the bone regrowth would take ten hours. She couldn't start repairing the gash until the bones had been regrown completely or the repaired tissue would have nothing to form over. Ginny would carry a cruel looking scar for the rest of her life, but she would live. Whoever had cut out the necrosis had done it quick enough to save her.
Hermione took Ginny's hand in her own and stroked it gently. She was covered in blood. Hermione cast cleaning charms across Ginny's body and changed her into into hospital robes with a few flicks of her wand. Then Hermione cast diagnostic charms over the rest of Ginny to ensure she wasn't injured anywhere else.
There was a scrape on her calf and bruising on one arm. Hermione fixed them in a few minutes.
Hermione stood and picked up both of the wands beside her.
“Sorry,” she said, handing Poppy her wand back. Grabbing a person's wand without permission was grossly offensive.
Poppy stashed her wand with a shaken expression.
“I had already cast four diagnostics before you came and none of them showed the remaining bone necrosis. I've never seen a diagnostic dissected compositionally before. I'm glad you didn't waste time asking permission.”
“I read about it in a book on healing theory. Brain diagnostics are difficult. There's so much activity that the magic picks up. They're hard even for specialists to read quickly. It was just luck it worked.”
Hermione sighed and wanted to sit down. Now that the crisis had passed, she was able to feel her heart pounding and her hands shaking. She felt light headed and on the verge of falling over backwards.
“I should go let everyone know she's alright,” she said shakily.
Harry and Ron and almost everyone else in Grimmauld Place were waiting outside the doors of the hospital ward.
“She's alright,” Hermione said as she opened the door. “She'll be alright.”
Harry gave a sob and slumped back against the wall.
“Oh, thank Merlin,” Charlie muttered.
Ron rubbed his eyes and Hermione saw blood on his hands and all over his clothing. She approached him and cast a subtle diagnostic as she did so. He was uninjured. It was all Ginny's blood.
“Did you remove the necrosis?” she asked Ron.
He nodded and his pale blue eyes flooded briefly with tears. His whole body was shaking as though he were going into shock.