Edna O?Brien?s 1997 Down by the River tells the story of 14-year-old Mary MacNamara, a victim of repeated paternal rapes. Based on the infamous 1995 ?X? case (in which a pregnant teenager was prevented from seeking an abortion after being raped by a friend?s father), it begins with the first rape and ends with Mary at the center of a national controversy over whether or not she should be allowed to flee to England for an abortion. I suggest that O?Brien makes one significant change to the ?X? case?introducing paternal incest?to evoke the tensions of Ireland?s colonial history. O?Brien?s works have been read by critics from both gender and colonial perspectives, but the presence of incest has not yet been linked to the colonial experience. Nation acts as family; and when, as in Down by the River , colonial oppression is internalized and expresses itself as sexuality, it invokes the recurring figure of incest. O?Brien directly targets the repression that still exists for women in highly patriarchal, colonial Ireland, a place in which the native men of the country have replaced the colonizing British presence, and abuse both sex and power to disastrous ends. This paper will explore Down by the River in post-colonial terms, specifically focusing on the repercussions of colonization for Irish women. Incest acts as a metaphor for the oppression of women in the novel, and the abusive Irish father and husband, himself at once both colonized and a colonizing oppressor in the family, rules over his women with a doubled brutality.