The story is based on the life of Hanaoka Seishu, Japanese physician, who lived from 1760-1835. The author, using Hanaoka’s personal papers, has created a fictional representation of the jealous hatred that grows between his mother and his wife living in their feudal Japanese household. The physician is involved in trying to develop an anesthetic which would enable surgeons to remove diseased breasts. The beautiful, widowed mother of the young surgeon begins to compete with his wife for the "privilege" of being his first human subject to take the toxic substances. The remainder of the story revolves around the complex relationship among the family members, with predictably unhappy outcomes, and the results of the experiment.