When she parrots the word back to him, Derek nods slowly, uncertain whether she's forgotten what he'd told her, whether the memory has been forcibly taken from her — because that's a thing that's possible in the Complex, from what he gathered — or whether she's just trying to process it now that it's something he could be potentially proving to her rather than simply telling her about. He's quiet for a moment while he watches her face and he smiles just a little once she seems to decide a few seconds before she speaks.

"Okay," he says agreeably enough. If she wants to see it, then he'll show her. Derek gently extricates his wrist from her hold and takes a little step back. "After I do it, follow me, okay? Alcide and I stashed clothes in a few places out here, so we're not far from one of my stashes. I'll make sure you can keep up," he assures her, a reminder mostly to himself not to take off running just because he can.

With that Derek takes a deep breath and lets it out slowly as he closes his eyes and rolls his neck on his shoulders to stretch a little. At first, nothing happens; at least, that's probably what it looks like to Katniss. To Derek, he's slipping into the mindset and finding his focus point. And then, just like that, in only a few seconds worth of time, Derek goes from a man standing upright and smoothly fades into an especially hairy man standing upright, to a wolf standing on its hind legs before finally dropping forward onto all fours. His eyes light up as he looks up at her and he bows his head just slightly as if to remind her that he isn't a threat just because he looks like one. He's still Derek in there.