In this thrilling silkpunk fantasy reminiscent of Mulan meets Iron Widow, eighteen-year-old Aihui Ying dreams of following in her father's footsteps to become a renowned engineer. However, her aspirations are shattered when her father is murdered, leaving her with only his journal of engineering secrets and a jade pendant taken from the assassin. Determined to uncover the truth behind her father's death, Ying disguises herself as her brother and infiltrates the male-only apprenticeship trial of the prestigious Engineers Guild. With the help of an unlikely ally, the taciturn eighth prince Aogiya Ye-yang, Ying navigates the trials while evading threats from jealous guild masters and a relentless killer. As her relationship with the prince becomes increasingly complex, Ying realizes that the secrets within the guild could be as deadly as the weapons they create. With her life and the fate of her homeland hanging in the balance, Ying must stay one step ahead of her adversaries and uncover the truth before it's too late.