Thy Brother's Wife opens in Nantucket, MA in 1825 on the wedding day of Haddie Elizabeth Starbuck, a young Quaker woman who, at 24, has already been twice widowed from Nantucket whalers. Both of her husbands came from the prominent Starbuck family. It is to the older brother of her two former husbands that she now prepares herself for marriage. During the wedding preparations a ship arrives and in addition to a belly full of whale oil, it carries Haddie's two lost loves, long since given up for dead by Haddie and the Quaker community. The perplexities posed by their return prompt Haddie to examine her role as a woman and a thinker in this liberated Society of Friends. And it prompts the brothers three to devise a plan whereby they could share the benefits of Haddie's companionship as a wife and mate on a rotating basis, for her benefit, of course. This play examines the moral and ethical dilemmas posed by the brothers' arrival and explores the relationship between the Quaker disavowal of violence against other human beings for any reason and their wholesale slaughter of whales solely for economic gain. Against this backdrop of moral and ethical complications, Haddie finds her own voice in the insular world of Quaker Nantucket and makes a decision to find her own place in the world as well.