Isaac had thought he would be ready for the full moon. Derek had pushed the new wolves harder than he ever had before in the week running up to it, teasing and mocking and taunting, and basically just being very Derek about the whole thing, seemingly willing to do anything if it meant they'd be ready.

Boyd had been his usual self; quiet and implacable, resolutely pushing himself up every time Derek knocked him off his feet. Erica, on the other hand, had fought and rebelled at every turn - or at least tried to. It had taken Derek less than an hour to snap, bringing out the big guns and going full on Alpha. He'd been physical, though not quite as bad as when he'd broken Isaac's arm. He regretted that, Isaac thought, not that Derek would ever say so, or apologise for it. Isaac himself had been doing his best, silently trying to force the wolf inside to work with him, rather than against him as was so often the case. There was no way to know until the night of the full moon had actually arrived, but he'd felt like he'd been making progress, felt like he could survive the night without ripping a few innocents to shreds. He hoped.

Derek spoke at length of an anchor, something that would keep them grounded when the change happened and the moon tried to exert it's power, something that would help them cling to a shred of humanity while the wolf raged. He had been tight-lipped when they asked about his own anchor, offering nothing more than a grunt, sometimes not even that, before walking away. Derek was trying, it was obvious, but it wasn't enough, couldn't be enough until he opened up to them.

Isaac snorts at the thought, drawing the eyes of his pack to him. Derek's glance is fleeting, already turning back to the manacles he's securing around Boyd's ankles. Boyd himself meets his eyes, lips drawing up slightly at the corners, an almost conspiratorial motion - he gets it, he's saying, he feels it too. Isaac can't help but be reassured - Boyd has that effect. Erica arches an eyebrow at him, trying to silently exude nonchalance. Trying a little too hard, Isaac notices. She feels it too, as much as she's desperately trying to hide it. The tautness of her cocky smirk and a frenetic cast to her eyes, darting around the dilapidated train carriage, never resting in one place for more than a few seconds, that shows she's not quite as poised as she'd have everyone believe.

An anchor. Isaac's turned the word over in his mind almost constantly since Derek first said it, analysing it, trying to find something in his own life that was strong enough to keep him human. A loved one is the obvious answer, but at this, Isaac almost snorts again, splayed fingers running through his hair. His mother is barely even a hazy memory, an echoed laugh and the ethereal feel of a warm, soft hand in his all that remains. He loves her, always will, but it's distant, a far removed feeling that he knows won't be strong enough. His father, then. Before the drinking and the shouting and the beating, the abuse - before it started, his father was great. Isaac can remember sitting beside him in the car, knees bouncing in anticipation as his father drove him to the comic store for the new edition of Spiderman. Can remember the first time his father took him to the park and taught him to play baseball, because he was nervous about asking to play with the other boys and then messing up. Can even remember the nights, just after his mother passed, that he'd wake up crying from a dream of her, only for his father to be there with a hug and consoling whispers. But these memories are tainted, laced with veins of darkness, the same darkness Isaac endured for hours on end when his father snapped and dragged him to the basement, when Isaac said the wrong thing and his father threw plates, glasses, punches. Isaac loves his father, he thinks, but this love is so tainted and warped by the hatred generated by years of abuse that it's something that festers inside of him, roiling and always there.

He's pulled from his thoughts by Derek asking him to hold Erica while he restrains her, and he doesn't miss the concern that tinges Derek's expression. His facade was slipping, apparently, unless it's a pack thing. They're all still getting used to what being a pack means, Derek included, so he's not sure. Erica's screams chill him as Derek tightens the screw, and he has to fight the urge to wrest the awful contraption from his hands and make the pain stop for her, for another member of the pack, and so he's able to focus on that and not the anxiety that's plaguing him about his 'anchor'.

He'll have to use his father, he knows; he doesn't have anything else. Anyone else. He'd be bitter about that, probably should be, he knows, but it's something he'd come to terms with a long time ago.

He panics when Derek starts to secure him. Asks again about controlling the beast he can feel rearing up within him, only to be met again with the same answer. It's different this time though, like Derek is desperate too, as he shares his own anchor. Anger. It makes sense, in a twisted kind of way, but Isaac doesn't want his only hope of humanity being borne from something so negative. Relying on the hatred he feels for his father would work, he senses, but if he goes down that route he's not sure if he'll be able to stop, to stop the hatred from consuming him.

There's the mention of Scott, who's so wrapped up in Allison that it actually makes Isaac a little nauseous. Well, it obviously works for McCall, but Isaac doesn't exactly have an Allison equivalent in his life right now. Not that he's had one before either. Since he's been turned, sure, girls (and not a few guys) had been throwing themselves at him, but there'd been so much crap going on in his life that he couldn't give them a second glance. It's not like he'd try to bring anyone else into the completely fucked up world he'd found himself in, anyway.

And then the dull thrum of the moon he's felt for the past few hours is a pounding that resonates throughout his whole body and the change is starting and all thoughts of an anchor are gone, swept away by the waves of pain that accompany the crack of bone as his body changes against his will. He's dimly aware of Erica and Boyd straining against their own bonds, but then the wolf takes his mind and his only thought is to reach the surface and hunt and kill. The chair he's manacled to is bending under the pressure already, and as Derek fights with Erica and Boyd, he's free and soaring through the window with a crash as Derek calls after him.

In some dark recess of his mind, Isaac fights vainly to think of his father, those scarce memories of him that shine bright and gold, but either the wolf is too strong, or more likely, Isaac suspects, his love for his father isn't enough, is too compromised by the veins of hatred that have permeated even those early memories.

He's bounding for the exit now, the wolf straining to scent the closest human, seeking warm flesh and warmer blood, and Derek isn't going to catch him in time and he's probably going to kill someone tonight and Isaac doesn't know what he'll do if he wakes up tomorrow covered in blood that doesn't belong to him. The wolf has picked up a scent though, one that's close and familiar to Isaac. He's stopped, searching the room for the source. Moves towards a pile of jackets, and as he gets closer the scent becomes overpowering, completely filling his mind, and suddenly the wolf is less dominant. Isaac is shocked at first, isn't sure what's happening, only that this scent is part of it, is the cause of his return to partial humanity.

He fumbles through the pile until he finds the scent, and then stops. He's holding the jacket Stiles left here after Erica had been injured by the kanima, and it's only then he connects the familiar scent with the person it belongs to. Stiles. Stupid Stiles, with his irritating, rambling manner, and his decrepit Jeep that he loved so much, and his goofy grin…

Isaac shakes himself, can't quite process what's happening. He's totally present now, the wolf tamped down, at least for now. All he knows is that he's in control, and that Stiles is the cause.

Stiles is his anchor. Stiles fucking Stilinski. God.

He makes his way back on to the ruined train carriage quickly, sensing that Erica and Boyd haven't been quite so fortunate as he. He's just in time to meet Boyd as he tries to leave, but he pushes him back easily, able to work with the wolf now. He nods at Derek to let him know that, yeah, he's in control. Derek looks as shocked as he feels.

When Derek inevitably asks about his anchor, he lies. Derek has to know, but in an uncharacteristic show of understanding, he lets it go, a frown flitting across his face the only sign that he knows Isaac isn't telling the complete truth. He lies because it should be his father, desperately wants it to be, but also because this thing with Stiles that he's apparently got going on, this Stiles thing is new and surprising and unprecedented, and Isaac sure as hell isn't letting Derek in on it before he's fully examined it.

Besides, it'd be kind of rude to tell Derek before Stiles.