In Huaxia, girls are sacrificed to pilot giant transforming robots known as Chrysalises alongside boys, battling the mecha aliens that lurk beyond the Great Wall. The girls rarely survive the mental strain—but 18-year-old Zetian has other plans.

Determined to avenge her sister's death at the hands of an ace male pilot, Zetian volunteers as a concubine-pilot. When she kills him through their psychic link and emerges unscathed, she becomes known as an Iron Widow—a feared and silenced kind of female pilot who can sacrifice boys instead.

Paired with Li Shimin, the strongest and most controversial male pilot in Huaxia, Zetian harnesses their combined might. But as she delves deeper into the misogynistic pilot system, enemies close in from all sides. Will Zetian survive long enough to stop more girls from being sacrificed?