One Big Happy Family is a gripping summer suspense thriller by bestselling author Jamie Day, published by Macmillan Publishers (St. Martin's Press). The novel is set at the Precipice, a legendary family-owned hotel perched on the rocky coast of Maine. Following the death of their father, the Bishop sisters—Iris, Vicki, and Faith—arrive for the weekend to claim their inheritance. With Hurricane Larry bearing down on the coast and each sister harboring dangerous secrets, murder is in the air, and not everyone who checks into the Precipice will be checking out.

At the center of the story is nineteen-year-old chambermaid Charley Kelley, who is smart, resilient, and in desperate straits. The arrival of the Bishop sisters threatens her livelihood and could expose her own secrets, including her habit of pilfering from guests and the fact that she's hiding a woman on the run in one of the guest rooms. The novel combines elements of a locked-room mystery with family drama, featuring razor-sharp wit, heart-pounding thrills, and unexpected twists. Published in hardcover format with 368 pages, the book has received praise from bestselling authors including Freida McFadden, who called it "an unputdownable and gripping thriller with nonstop twists and turns." The Minneapolis Star-Tribune noted the book's "sharp Knives Out vibe," while readers have compared its family dynamics to the Succession series. Jamie Day is also the author of The Block Party, another acclaimed thriller.