The play, set on an island off the coast of Ireland, begins with Nora bringing in a small bundle with her and telling Cathleen that these may be the clothes of their brother Michael. The young priest told her a body of a drowned man was found at Donegal, and the body might be Michael's. The sisters are scared to open the bundle of clothes because they do not want their mother, Maurya, to know: Michael has been missing for a week and the family had already lost five men to the sea. They hide the bundle in the turf loft of the cottage.
Maurya is prepared for the funeral for Michael, with whiteboards for his coffin ready at the cottage. She enters the kitchen; she is a woman who is seen lamenting all the time and worrying that her sons will never come back from the sea. Maurya, Nora, and Cathleen discuss the last son, Bartley, who is also planning to go the sea to sell the family horses so they could get some money. Nora and Cathleen are convinced that Bartley should go to the fair at Galway to sell the animals, while Maurya is still hoping that the Priest will not allow him to go in such dangerous tides.
Bartley enters the cottage looking for a new piece of rope. Maurya tries to stop him, but he says he wants to make a halter for the horses; clearly Bartley plans to go to the sea. Maurya again tries to dissuade him by showing him the whiteboards for Michael. Paying no heed, Bartley changes his clothes, asks his sisters to take care of the sheep, and leaves without receiving any blessings from his mother. It is a tradition in Ireland that the son receives the blessings of his mother before going anywhere, but Maurya breaks this fashion.
Bartley leaves with a red mare and a grey pony tied behind. Cathleen then notices that he has not taken any food and tells Maurya to walk down to the well to give Bartley his food and the blessings. Maurya leaves using a stick that Michael brought, lamenting over how in her family, the old ones never leave anything behind for their heirs, despite that being the general custom.
Once Maurya is gone, the girls retrieve the bundle of clothes from the loft to check if they are Michael's. Nora realizes that the stockings are truly Michael's, because she recognizes her own stitching on them. They count the number of stitches and arrive at the conclusion that Michael was dead and buried.
The sisters hide the clothes again because they think that Maurya will be returning in a good mood since she got the chance to bless Bartley; however, Maurya comes back more distressed than ever. She tells her daughters that she saw Michael on the grey pony; she could not bless Bartley due to the shock. To calm her down, Nora and Cathleen show Maurya the clothes and tell her that Michael has had a clean burial. Maurya's laments are interrupted when islanders bring the body of Bartley into the cottage and tell the women that the grey pony knocked Bartley into the sea, where he drowned.
Maurya gets on her knees near Bartley's body and sprinkles holy water on him. She finally resigns herself to her fate as she claims that she will finally sleep at night because she no longer has anyone to worry about: all the men of her family have died to the sea. The whiteboards that were supposed to be used for Michael's coffin will now be used to bury Bartley. Maurya prays that the souls of her husband, her husband's father, and four sons may rest in peace, and the curtains are drawn.