Three masters of Cangwushan let their disciple Zhou Dashi go down the mountain to handle three old engagement contracts and recover old debts of the sect. Zhou Dashi is successively embroiled in the Tang family's equity dispute, Su Wantang's blindness poison case, and the Shen family's poisonous incense old case. Relying on his martial arts, medical skills, and poison-distinguishing ability, he investigates the truth, exposes the conspiracies of Shen Mantuo and Shen Yunluo, rescues the third master, and defends Jiuxiaomen. After all the old engagement contracts are voided, he re-proposes to Su Wantang according to his own heart, completing his growth from canceling engagements to independent choice.