The play opens inside a cottage "close to Killala," 1798. Bridget is standing opening a parcel, while Peter, her husband, sits by the fire with Patrick, their 12-year-old son. Peter and Patrick talk about the fact that they can hear cheering outside, and Patrick goes to investigate. Peter thinks it might be for a hurling match, but Patrick suggests it's coming from the town.
Bridget calls Peter over to look at their older son Michael's wedding clothes. They discuss the fact that they were not dressed so well for their own wedding, and never even dreamed that they would have a son who dressed so well for his own wedding. Patrick sees an old woman coming down the road towards the house, and thinks she is a stranger. He asks, "Do you remember what Winny of the Cross Roads was saying the other night about the strange woman that goes through the country whatever time there's war or trouble coming?"
Bridget shrugs this off and tells Patrick to open the door for Michael, and Peter says he hopes that Michael has brought his fiancée's fortune safely, so that her family does not go back on the offer. Michael enters and tells his parents that he visited the priest, who said "he was never better pleased to marry any two in his parish than myself and Delia Cahel." They ask him if he has the fortune from the Cahels and Peter talks about the fact that Old John Cahel wanted to withhold half the fortune until Delia and Michael had their first son, but that he talked him out of it.
Peter talks about the fact that he did not fetch 100 pounds when he married Bridget and she fires back, "Well, if I didn't bring much I didn't get much." She is mad and says, "If I brought no fortune, I worked it out in my bones, laying down the baby, Michael that is standing there now, on a stook of straw, while I dug the potatoes, and never asking big dresses or anything but to be working."
The play begins with a simple Irish family home, where Bridget and Peter are preparing for their son Michael's betrothal to a wealthier girl. As they wait for him to return home, they discuss the fact that they did not wear such fine clothes to their own wedding, and express their hopes that Michael has safely procured the fortune that he has gained for the wedding to his betrothed, Delia. Keats and Lady Gregory depict a scene of economic exchange, exposing the ways that marriage is a business transaction, rather than simply a romantic arrangement.
Indeed, money is the chief concern for Bridget and Peter, and it seems to have been the chief concern for Delia's father as well. Peter talks about the fact that Delia's father wanted to withhold half of the dowry until she had produced a son, but Peter convinced him to hand all of it over. In this we can see that not only is this a society that looks at marriage primarily as an economic proposition, but one in which sons are prized above daughters, and in which the bride's father can hold back his offering as if he were making a business deal.
Also in this first section, the characters bring up a local legend that will be important for the plot. Apparently, someone named Winny told them that there is a certain strange old woman whose arrival in the town signals imminent misfortune or war. Patrick imagines that the woman he sees walking down the road is that woman, and that her arrival might be symbolic, but Bridget suggests that this is ridiculous and encourages him to think of something else. They get back to talking about Michael's wedding almost immediately.
The play is a small and simple play, only one act long and not many pages, yet its meaning and substance are significant. The titular Cathleen Ni Houlihan is not someone that Yeats and Lady Gregory invented themselves, but a mythic figure in Irish culture, and a symbol of Irish nationalist politics. In popular myth, she is an old woman who is not only representing a coming war, but also encouraging young people to begin that war on behalf of Irish independence. Yeats and Gregory stage this myth in the context of this fictional family, and create a play that is notably political in its content.
Yeats and Lady Gregory split the writing duties on the play, with Gregory writing all of the dialogue of the central family, a peasant Irish brood who try and take care of one another even when life is tough and they slip into resentment. Bridget and Peter fight about the fact that their son Michael is marrying a wealthy woman and recall the fact that they did not have the same luck. Peter suggests that he did not make any money from marrying Bridget, and she becomes angry, insisting that she did not get much back in return, and never once asked for anything special from him. Thus, some intergenerational tension is set up in this beginning scene.