The novel opens with a flash-forward: An older Polly reflects on life on Mount Polbearne, a tidal island off the Cornish coast, describing it as lovely despite its initial awfulness.
In 2014, Polly Waterford and her partner Chris sit in the wreckage of their graphic design firm in Plymouth as bank representatives guide them through bankruptcy. They launched the business seven years earlier, but the 2008 financial crisis and new technology eroded their client base. Chris withdrew emotionally, hiding the extent of their debt, while Polly exhausted herself chasing new business. Their relationship deteriorated alongside the company. Now the bank is taking their flat, and Chris plans to move to his mother's house.
Polly's best friend Kerensa, a management consultant, helps her search for housing, but everything in Plymouth is squalid or overpriced. Broadening her search, Polly finds a listing on Mount Polbearne, a tidal island she vaguely remembers from a school trip: a flat above an abandoned bakery with a vast gray sea view that resonates with her emotional state. She and Kerensa visit, crossing the cobbled causeway that connects the island to the mainland only at low tide. The flat is dilapidated, but it has an enormous iron oven and a striking view. Polly negotiates the rent down and signs a short lease.
She moves alone after a quiet farewell with Chris, bringing her sofa, coffee machine, and bread mixer. On her first day, wind blows her childhood copy of
Alice in Wonderland onto a fishing boat. Tarnie, the bearded captain of the vessel
Trochilus, returns the book, and his crew helps haul her furniture upstairs. That night, Polly discovers a baby puffin with a broken wing in the shop below. She bandages it, names it Neil despite the local vet's warning not to get attached, and begins carrying the bird in her rucksack.
Polly bakes her first loaf in the old oven and experiences a cathartic release, crying as she kneads. She shares the bread with the fishermen, who love it. Jayden, a young member of Tarnie's crew, suggests pairing it with local honey and mentions a ghost that supposedly haunts the harbor at night. Gillian Manse, who runs the town's only bakery and serves as Polly's landlady, confronts Polly on the harbor, accusing her of undermining the business and threatening her tenancy. Undaunted, Polly begins selling bread covertly to villagers.
Following a sign for honey, Polly discovers a thatched cottage belonging to Huckle, a tall, blond American from Savannah, Georgia, who keeps bees. He gives her honey in exchange for future bread and deflects all questions about his past. They develop an easy friendship.
One night, Polly spots the "ghost" on the harbor wall and shouts, startling the figure, which falls into the water. She drags the unconscious Mrs. Manse from the freezing harbor and calls Huckle for help. Tarnie reveals Gillian's tragic history: Her husband and son were lost at sea nearly 20 years earlier, their bodies never recovered. The figure Jayden described is Mrs. Manse, who stands on the harbor wall at night, still waiting for her family. Overcome with guilt, Polly cleans the neglected bakery and bakes treats for the hospitalized woman.
Tarnie arranges for Polly to work at Gillian's shop, but Gillian criticizes everything and refuses innovation. Huckle suggests splitting operations. Reuben Finkle, a brash Silicon Valley millionaire and Huckle's friend, sends a brick oven as a gift. Mrs. Manse reluctantly agrees, and Polly opens the Little Beach Street Bakery below her flat, selling out on her first day. Huckle takes Polly on his motorcycle to deliver a healed Neil to a puffin sanctuary on the north coast, tagging the bird's leg with a "Huckle Honey" seal so Polly can identify him.
Over the summer, Polly and Tarnie begin a tentative relationship, but Jayden accidentally reveals that Tarnie is married: His wife Selina lives on the mainland. Polly is furious and humiliated. She pushes the revelation aside to host visiting Chris, who asks her to take on their old flat's mortgage so he can return to Plymouth. Gazing at the lighthouse beam sweeping across the harbor, Polly realizes she does not want her old life and tells him so. Chris leaves the next morning but paints the bakery exterior a soft gray and letters its name in his beautiful script.
One evening at Huckle's cottage, he reveals his backstory: He was an executive in Savannah whose long-term girlfriend, Candice, left him for a wealthier man, prompting his move to England. He and Polly share emotional intimacy but do not act on it.
A catastrophic storm hits Mount Polbearne. The fishing fleet goes out despite the weather, and over two agonizing days the other crews are recovered, but Tarnie's boat remains missing. Reuben and Huckle take a speedboat to search, finding the surviving crew in their survival capsule, including a badly injured Jayden, but Tarnie is not among them. He freed Jayden from a broken mast but was pulled under by the sinking ship. That night, Polly finds Mrs. Manse on the harbor wall. The old woman begs Polly not to become like her, forever waiting for someone the sea has taken.
A memorial service fills the ruined hilltop church. Afterward, Neil returns, flying all the way from the sanctuary to bang on Polly's window. At Reuben's extravagant beach wake, Polly tells Huckle she would have liked to make him happy. He kisses her fiercely, but she pulls away, feeling it is wrong at Tarnie's memorial. Huckle misinterprets her withdrawal as lingering feelings for Tarnie and shuts down emotionally.
Huckle abruptly leaves for Savannah, texting Polly only to ask her to arrange a beekeeper for his cottage. An incompetent temp arrives; Polly sends him away and begins tending the hives herself. Mrs. Manse retires, entrusting Polly with both bakeries. Jayden, refusing to return to fishing after his ordeal, becomes Polly's capable assistant. Chris sends word that their Plymouth flat has sold and their debts are cleared. Kerensa announces her engagement to Reuben.
At their
Star Wars-themed wedding on Cape Cod, Polly is maid of honor dressed as Princess Leia; Huckle is best man dressed as Han Solo. The connection is immediate. They slip away to the beach and spend the night together, but an impasse follows: Huckle asks Polly to stay in Savannah, and Polly asks him to return to Polbearne. Neither can yield. Polly has built the bakery from nothing and feels responsible for it; Huckle has reestablished his career and sees Polbearne as a temporary escape. Polly flies home heartbroken.
Back in Polbearne, Polly continues running both bakeries and tending Huckle's bees. In Savannah, Huckle calls the temp agency and learns no one has visited his cottage in months. Polly has been caring for his bees all along. The revelation undoes him. He flies to England, finds the hives immaculately maintained, and races his motorcycle to the causeway, where the entire town stands in a human chain protesting a proposed bridge to the mainland. He pushes through the crowd as the tide rises. He and Polly collide in the middle of the flooding causeway and kiss as water laps at their waists, then wade to shore laughing and soaked.
The photograph of their embrace goes viral, and the council votes against the bridge. Polly and Huckle stand atop the old lighthouse, looking out at the sea with Neil flying happily around the circular room. They agree to buy it together. As the fishing fleet heads out at sunset, Polly murmurs "Godspeed," feeling at last that she is exactly where she belongs.