The Bellas are a close-knit Italian-American family in Boston, anchored by Joe [Danny Aiello] Bella and his wife Marilyn [Gena Rowlands] Bella, who run a construction company and keep a bustling household. They have three children—Renata [Holly Hunter], Tony [Danton Stone], and Jan [Laura San Giacomo]—with Jan about to marry. Renata, the eldest and still unmarried, begins to wonder why her longtime boyfriend Rob [Griffin Dunne] hasn’t proposed.
Renata travels to the Caribbean to take a course on selling condominiums, where she meets Sam Sharpe [Richard Dreyfuss], a highly successful Lithuanian-American salesman who delivers a powerful speech at a training seminar. The connection between them is immediate, and Sam accompanies Renata back to Boston to meet the family. The Bellas are warm enough to include him, though Jan initially resists, testing the family dynamics and bringing a tensed balance to the siblings’ usually tight rapport. After a heartfelt moment, Jan apologizes and offers her blessing.
Sam and Renata marry, and he relocates his business from New York to Boston so he can devote more time to his new life. At a memorial for Joe’s late mother, Sam’s attempt to sing a personal tribute is met with amusement and discomfort by the family, especially Marilyn, who feels the moment is inappropriate. Renata confronts him, arguing that he might be tearing the family apart; they work through it, and soon Renata gives birth to their daughter, a bright ribbon of new life for the family.
The baptism of Renata and Sam’s child is a turning point when Sam suffers a heart attack and is rushed to the hospital. Now confined to a wheelchair, he returns home to celebrate Christmas with the Bellas. During dinner, he lights a cigarette, which Renata (with quiet resolve) extinguishes in a glass of wine. On a frozen lake, Renata goes skating while Sam and their daughter watch from the shore. Tragically, Sam passes away, holding his child as his final gift to a life he helped shape.
In the aftermath, Renata mourns, but also cherishes the profound changes Sam brought to her life and to the family. Joe carries a final, intimate memory into the funeral procession, guiding it through several slow rotations on a traffic round-about—a small, hopeful ritual that Sam had learned from his father-in-law and cherished during his life.