A/N : I'll warn you now, this could get rather grim...

Stepping lightly downstairs, silent in fluffy slippers, Wanda couldn't help but think that things were far too silent down there. No radio playing, no chatter, not even Lorna's barely-intelligible vocalisations. Wrapping her robe around her, she padded into the kitchen, sat down at the table. Her mother looked exhausted, dark puffy circles under her eyes, raising another spoonful of soggy cornflakes to Lorna's mouth. The kid looked shell-shocked, opened her mouth mechanically and took the dripping spoonful without protest. That wasn't right, Wanda thought. For one thing, Lorna could feed herself with little difficulty now, and for another she was infamously tantrum-prone and peevish in the mornings, not at all given to sitting quietly and letting Magda shovel food into her mouth.

"Is Peter sleeping?" the girl asked cautiously. Poured some juice. Her mother didn't turn, but shoved a note across the table in her direction. She could tell by the atrocious handwriting and spelling that her brother had written it – he might be bright, but he didn't pay a whole lot of attention in school and consequently he wrote like a little kid.

"With Dad" she read, "Dont worrey. Gowing to the docters"

She didn't say anything for a few minutes. Tried to pick up her glass but found her hands too shaky. Peter had never been away from the house for more than a couple of hours before, and to suddenly not know where he was or if he was safe made her feel like the foundations of her world were being violently shaken. She couldn't imagine being parted from him, not squabbling on the way to school tomorrow morning, not sitting beside him in class. Being referred to by name by their teachers, instead of just 'the twins'. Wanda felt as though part of her had been cut out – something important and bloody.

"When's he coming home?" she asked. Her mother turned on her with a fury

"The hell should I know, Wanda?!" she yelled, a high pitch of fear in her voice, underscoring the anger like discordant strings, "he took off some time last night, your father's probably dragging him to some witch-doctor by now, god knows if he even made it there alive!"

"Mom…" Wanda wasn't a tearful person, but felt her eyes growing hot and filling up, "Don't say that!"

At last Magda looked at her. Her eyes were so raw and bloodshot that Wanda worried they were hurt somehow, looking almost on the verge of bleeding. Lorna stared at them both. She looked as if she would start squalling if she were not frightened into shocked silence. Under her terror, Wanda could see a cold, accusatory anger.

"Go to your room," she said, voice flat, "Do your homework, call boys, listen to that trashy music, do what you like – just don't let me set eyes on you again today"

Wanda stared at her for a moment, heart pounding, feeling like her eyes would overflow. Then she stood, sniffed, walked away from the table and back up the stairs to her room. Behind her, she could hear her baby sister starting to scream, their mother shushing her tenderly.

Erik had nothing to do but wait.

The Mansion was virtually empty, most of the residents being away on business of one sort of another, leaving only Sean Cassidy and Hank McCoy to run things, which meant Hank was doing everything. Sean was a good kid, his heart was in the right place, but he couldn't organise his way out of a wet paper bag. He had been grateful to find the doctor at home, happy to hand his son over to him, but now all could do was wander the halls and grounds waiting for Hank to finish his examination. He was sure Peter would have been a lot more surprised to find himself handed into the care of a seven-foot tall blue apelike creature, if he hadn't been half-conscious with exhaustion by the time they had made the long drive to Westchester. He'd kept half an eye on the boy, hardly able to hold his head up, smothered under a couple of thick rugs and still shivering, watching him grow more grey and shattered-looking as the hours passed by, wondered how long Magda had kept it from him that his son was so sick. He hadn't spent much time with Peter for months, away on business and unable to fit in a proper visit around the boy's school commitments. Looking at him now it was painfully obvious that any baby-fat he'd had had fallen off him, and he'd never been a chubby child to begin with. He didn't look like he'd had a good night's sleep in months, shaky and catastrophically weary but somehow still unable to fully doze off. Erik had quickly realised that the pain he'd complained of was not just a little cramp, but debilitating weakness and agony that came from deep in his bones and radiated out to fill every part of him, and was deeply sorry for having dismissed it once he had realised the extent of his suffering.

At last, Hank had emerged, Erik immediately rushing to him and beginning a flood of questions which the furry Mutant had silenced with a hand, ushering him over to a chair and sitting down with him.

"Where is my son?" he asked

"Sleeping – I've anaesthetised him. He hasn't slept in ten days, he'll start hallucinating soon if he doesn't rest. Why didn't you bring him sooner, Erik? He's deathly ill, he could have died without intervention"

Erik shook his head. Felt responsible and furious and helpless

"I didn't know," he said, "His mother and I… well…." Hank gave him a small, understanding sort of smile. Squeezed his shoulder. "Is he….?"

"He has an active X-gene, yes. He's a Mutant"

A sense of unexpected relief flushed through Erik, and he even managed to return Hank's smile a very little. Felt a tiny glimmer of hope kindle at the news.

"Can you treat him?"

"I don't know," Hank said sincerely, "As far as I can see, his body is attempting to reform itself, whatever mutation he settles with is taking a very long time to come on. His metabolic rate is through the roof, he's not able to get enough calories to meet his needs – which is why he's lost so much weight and feels so tired all the time. At the same time, his mind is running at an incredible speed – his perception and reflexes are like nothing I've ever seen before despite the fact he's absolutely worn out. And… well…."

"Well?" Erik prompted, knotting his hands in concern, "Well what?"

"There's no way of putting this gently. His bones are crumbling, whether that's due to an emerging mutation or malnutrition I can't say, but that's why he's in so much pain. He's falling to pieces Erik. He must be very brave to put up with all that"

Erik stared at his knotted fingers. Brave was not a word he would ever have used to describe his son – needy, clingy, immature, dense, but never brave. For a while he simply let it sink in, the pain that he had been concealing from everyone, and how he had underestimated him, before finally he had said

"What can you do?"

Hank licked his lips, took off his glasses and began to methodically polish them – it was a habit Erik knew well, and knew that it meant he was stalling for thinking time. Eventually, he slipped them back on, having difficulty meeting Erik's steely gaze as he replied

"I'm sure you know there's only one reason mutations arise, at the end of the day" he said, tried to keep his voice soothing, "Need. If we need it, we can be pushed to it. The early hominids evolved with darkly-pigmented skin because they needed the protection of melanin under the equatorial sun. Arctic mammals evolved thick layers of body fat to keep them warm. If we exert a pressure, mutations arise"

"Hank, my son is not a polar bear. I would very much appreciate you getting to your bloody point"

"Most of the Mutants I've seen have found out about their powers in times of extreme stress… you, in fact, if I remember rightly…."

He trailed off, saw the look of pain cross Erik's face. Was glad that he did not have Charles' gift at that point – he could not have borne the horrors that had brought Erik's metal-manipulation to the fore.

"My only idea is that given enough stress, we might bring his mutation on faster. The problem being, he's so physically weak that the amount of stress it would take –"

"Might kill him" Erik interrupted. Hank nodded.

"I'm so sorry, Erik. I don't have any other answers for you. I can stabilise his condition and make him comfortable, but unless he fully mutates soon, he has a good few years of feeling like this ahead of him. And he might not survive it. He's already very run-down, seriously underweight and desperately exhausted, I simply can't say how much more of that he can take."

For the longest time, Erik stared at his white knuckles, at the floorboards, at nothing in particular. Sat as still as stone, until he had finally said in a quiet, hoarse voice.

"What kind of stress would do it?"