Shen Wanning, the concubine-born daughter of the Shen family, was plotted against by her family to marry far away to the frontier in place of her legitimate sister Shen Yutang. The marriage contract unexpectedly hid half of the Zhenbei military seal, reducing her to an abandoned pawn. Along the way, she repeatedly faced assassination attempts and happened to meet Pei Zhaoheng, the deputy general of the Zhenbei army who was dormant at the frontier and carrying an old case. At this time, frontier military medicine was shrouded in suspicion, the Lu family and Thousand-Householder Han colluded to traffic fake medicine, and the Shen family was also deeply trapped in the conspiracy, attempting to frame the Pei family through her. Shen Wanning, who knows medical arts, joined hands with Pei Zhaoheng to tear open the fake medicine dark curtain and investigate the truth of the unjust case from three years ago. She broke free from the shackles of her original family, and at the snowy frontier, guarded her own destiny and justice.