Severus had been surveying it carefully until her warning.
He looked up and sneered at her. “Thank you, Miss Granger, without your warning it would never have occurred to me to be cautious with a bomb.”
Hermione didn't blink. “Would you rather I not mention it's delicate?” She arched her eyebrows. “It's designed to target the magic keeping us out of Hogwarts, so the higher you can get it, the better. The Astronomy tower would be ideal. It has some combustive power, but it's primarily designed to break the wards, the lower it is at detonation, the less impact it will have. At least — well, it's based entirely on arithmancy — I couldn't actually test it.”
“I'm overcome with confidence,” Severus said, looking down at it again.
Hermione was so nervous her chest felt fractured. Lately it was a constant, grinding pain until she could barely breathe.
“I was unaware you had added bomb-making to your repertoire,” Severus said after a minute.
Hermione pulled off a heavy dragonhide apron and gloves and looked down at her hands, wincing. Her skin was speckled with burns, and several fingertips were green and withered; she'd have to carve off the remaining tissue and regrow it. Protective clothing and wards had limited effect when working with materials specifically chosen for their ability to destroy protection.
She rubbed her fingers together and watched as the skin cracked and fell off, leaving the bones exposed in places.
She grimaced and carefully wrapped bandages infused with essence of Dittany around her hands. “I started after we heard about the Albanian hospital — just the theory. I didn't understand the reports, and I felt guilty that maybe it was partly my fault that the hospital had been targeted. I thought I should at least know what happened to everyone there. Then — after the raid on the labs of the curse division — I had everything, but it wasn't even worth trying to propose that the Order use a bomb.”
She shrugged and started packing up her materials into all their carefully sealed and cushioned boxes and containers while Severus watched.
They were in an abandoned barn in the countryside that the Order had sectioned off for Hermione to work in. Initially, there had only been half-hearted objections made when the idea of using a bomb was proposed, but in the end the Order had agreed. No one had a better idea, and after half a year, and dozens of casualties from the attempts, there was a sense of raw desperation in everyone.
Hermione gingerly placed a flask, still half-full of shimmering, silver liquid, into a warded box and sealed it with several protective spells. “When Bill brought his analysis of the wards on Hogwarts last month, I realised that there was a chance I could combine charmwork and arithmancy with the traditional use of potions and alchemy for explosives. I was rereading Dumbledore's collaboration with Flamel on the uses of dragon's blood and had the idea that it would react with silver nitrate dissolved in unicorn blood powerfully enough to dissolve the wards. The main challenge was finding a way to suspend it in something that could penetrate and adhere to the magic, so I used manticore venom to emulsify it. The detonation is primarily intended to create a blast radius large enough to destabilise and collapse the wards when the solvent hits it. I ran the numbers dozens of times before I brought the proposal to Moody; I'm almost positive I've calculated it all correctly.”
She caught herself rambling and stopped, looking up at Severus.
As he studied her, his eyes glittered. Then his mouth pursed, and he stared back down at the bomb between them. “Are Potions and healing such tedious wartime careers that you must invent an entirely new field of magic in order to preoccupy yourself?”
Hermione felt her cheeks warm. Her eyes dropped as the corner of her mouth quirked. “I thought it seemed like a logical way to combine the branches.”
“You would,” Severus said with muffled snort. “If this explodes prematurely, I hope you will recall all the occasions in which I answered your incessant questions with the reminder that just because a thing can be imagined by you, doesn't mean it should be attempted.”
He sighed. “You always were an insufferable student to teach.” There was a pause as he eyed the bomb again. “This is precisely why.”
Hermione ducked her head to hide a smile.
That night she apparated to Whitecroft and waited nearly half an hour before Draco appeared.
She'd barely seen Draco since he'd returned from his trip. He'd brought the occasional report and renewed warnings that Voldemort was likely preparing for his own final blow. More Death Eaters than merely Lucius were being brought back to England.
She'd decided, from the beginning, not to mention her most recent occupation within the Order.
When he appeared in the shack, he was dressed in formal robes, and his expression was braced. It was as though he had expected to find her bleeding to death on the floor.
Relief flooded across his face as he stared at her. “I can't stay unless it's an emergency, I'm at a dinner. What is it?”
She wanted to reach out and touch him, but she held herself back. Her fingers still hadn't fully healed; she had them carefully glamoured to hide the scarring.
“I was sent to tell you the Resistance will attack Hogwarts in two days. It will begin at precisely noon.”
His jaw twitched. “I'm assuming you will not be there.”
Hermione nodded. “I'll be in the hospital.”
His eyes narrowed as he kept studying her. “The Order found a way through the wards?”
Hermione didn't react. “Yes. The wards have been taken into account.”
“What do you need me to do?”
She licked her lips and curled her left hand into a tight fist. “Harry will be there. We want a final confrontation, but before we can do that, we need to kill Nagini. Harry says he's positive she's a horcrux. Either get her brought or find a way to kill her when she's left behind.”
His eyes gleamed. “If the Dark Lord appears, she'll be there.”
“Good.” Hermione gave a sharp nod. “That's all we need.”
She turned to leave, but Draco stepped forward and caught her arm. His eyes were dark as he closed in on her. “Come back. Tonight.”
She shook her head firmly. “You said we couldn't, Draco. This isn't a time to take risks.”
She tried to back away, but his other hand caught her hip, and he backed her into the door. He seemed to have forgotten he was the one who couldn't linger.
“I want to see you.” He slid his hand up her arm to her jaw, tilting her face up towards his.
Hermione's breath caught, and she shivered.
She was cold. She was so cold, and he was warm.
It might be the last time.
She wavered. “Alright. I'll come. You have go now though.”
He let go of her. “I'll call you.”
She nodded, and he vanished without a sound.
She went back to Grimmauld Place and carefully finished healing her hands until the scarring was almost undetectable. The fingerprints on her right hand were gone, but unless she looked for them under certain light, it barely showed.
She traced her fingers down her sternum. With treatment, the scars on her chest had faded so that the injury was less mangled looking. Her inner breasts had been pocked with acid burns all the way into the mammary tissue, which she'd managed to restore somewhat. The scarring, however, was permanent. The best she could do was treat them so that the scar tissue was elastic and add cumulative glamours so the injury would fade and become less discolored and painful looking.
It was three in the morning when her ring burned.
Draco appeared the instant she stepped into the shack and apparated them. She found herself crushed against the wall as his lips found hers, and he ravenously kissed her.