Plot
In a small remote Irish fishing village, Aileen (Watson) works as a shift manager at the local seafood processing plant alongside Mary (O'Dwyer), whose son Mark recently drowned at sea, and Sarah (Franciosi), a young woman experiencing marital troubles with her husband Francie (McCormack). At Mark's funeral reception, Aileen's estranged son Brian (Mescal) unexpectedly returns after a lengthy and unexplained move to Australia. While initially caught off-guard, Aileen is delighted to reunite her family together alongside husband Con (Conlon), daughter Erin (O'Rourke) with her newborn son, and elderly father-in-law Paddy (Roddy) who is in a vegetative state.
Brian remains vague about Australia, but expresses his intention to restart the family oyster trapping farm that was abandoned after his departure. Since Brian has no money or resources of his own, Aileen steals bags of oysters from the plant to seed his traps, which is witnessed by Sarah. The next day, local seafood supplier Francie is irate over missing oysters from his order. Aileen blames a lower worker, and finds Sarah heartbroken about her decision to separate from Francie.
At home, Con confronts Brian about stealing fish from others' traps and selling them himself. Brian storms off and later begins working for another fisherman. Aileen and Brian visit the local pub, where they notice Sarah arrive alone. Brian attempts to rekindle a former romantic relationship they shared in their teenage years, and Aileen returns home by herself.
The following day, fungus is discovered on the oysters at the processing plant and a moratorium is declared, devastating the community. Amidst the announcement, an already distressed Sarah faints unexpectedly. Aileen receives a call from the police stating that a sexual assault claim has been filed against Brian, who claims that he was at home with his mother the night of their bar outing. She lies to the officer confirming his alibi, and does not question Brian when they drive back home. Sarah goes missing from her shifts.
Erin visits Sarah, who confesses the events of the sexual assault following the bar encounter. Her story begins to leak around town, namely with the factory coworkers. Aileen, Brian, and Sarah are summoned to court, where Aileen testifies once more that she was home with Brian during the incident. The court throws out the case due to lack of physical evidence, much to the dismay of Sarah. When Sarah returns back to the processing plant, she is let go due to her repeated absences. On her way out she alludes to Aileen being the cause of Francie's missing oysters, and Aileen is sent home. At work, the coworkers begin to avoid Aileen, while in the village, Sarah is ostracized by the men.
As Aileen becomes haunted by the guilt from her actions, Paddy suddenly dies in his sleep. At the wake, Sarah makes an appearance and spits at Brian. Aileen stops Brian from retaliating. During the reception, an unaffected Brian is seen flirting with a younger girl, Emma, and Aileen steps in. Brian loses his temper, and a physical scuffle ensues between him and Con.
Following their fight, Brian sets out to the family's oyster plots accompanied with Aileen, who finally confronts him about his assault against Sarah. Brian dismisses her. Noticing the rising tide, Aileen returns back to the boat while the waves quickly overwhelm Brian, who drowns.
Afterwards, Aileen tells Sarah to stay in the village. Sarah decides that there is too much negative history plaguing her in the town, and drives off ready to start a new life.
