The six hoverboards slipped among the trees with the lightning grace of playing cards thrown flat and spinning. The riders ducked and weaved among ice-heavy branches, laughing, knees bent and arms outstretched. In their wake glowed a crystal rain, tiny icicles shaken from the pine needles to fall behind, aflame with moonlight.

Tally felt everything with an icy clarity: the brittle, freezing wind across her bare hands, the shifting gravities that pressed her feet against the hoverboard. She breathed in the forest, tendrils of pine coating her throat and tongue, thick as syrup.

The cold air seemed to make sounds crisper: The loose tail of her dorm jacket cracked like a wind-whipped flag, her grippy shoes squeaked against the hoverboard surface with every turn. Fausto was pumping dance music straight through her skintenna, but that was silent to the world outside. Over its frantic beat Tally heard every twitch of her new monofilament-sheathed muscles.

She squinted against the cold, eyes watering, but the tears made her vision even sharper. Icicles whipped past in glittering streaks, and moonlight silvered the world, like an old, colorless movie come flickering to life.

That was the thing about being a Cutter: Everything was icy now, as if the world were opening her skin. Shay swooped in beside Tally, their fingers brushing for a moment, and flashed a smile. Tally tried to return it, but something shifted in her stomach as she looked at Shay's face. The five Cutters were undercover tonight, black irises hidden under dull-eyed contacts, cruel-pretty jaws softened by smart-plastic masks.