Someone Else’s Secret by Julia Spiro, Lake Union Publishing, 2020, 415 pages, $14.95

Lindsey Davis, the main character in Julia Spiro’s debut novel Someone Else’s Secret, is at loose ends in 2009. She’s just graduated from Bowdoin College with a very expensive degree in art, but the Great Recession of 2008 has cratered the U.S. economy and suddenly Lindsey feels like her dreams of becoming a curator at Boston’s Museum of Fine Arts will never come true.

Then her college advisor introduces her to Jonathan and Carol Decker and hints the Deckers might present an opportunity she shouldn’t turn down. But instead of an internship the reality is far more mundane: the Deckers have unexpectedly lost their nanny and require somebody to look after their two children during the family’s upcoming stay on Martha’s Vineyard. Lindsey knows the Deckers are well-connected in the arts world, and her only other prospect is to go back (under a mountain of student debt) to live with her parents in Maryland.

The couple’s two children (five-year-old Berty and 14-year-old Georgie) alternate between surly impassivity and rude acting-out. “Just the act of watching them from a distance was exhausting,” Lindsey thinks, but Jonathan Decker is on the board of the MFA, and he’s quick to promise Lindsey help with finding a job once the temporary nanny gig is over.

“I can help you, Lindsey,” Jonathan tells her, putting a warm hand on her shoulder with perhaps a bit too much emphasis, while his wife looks on with “wintry elegance.”

Lindsey accepts the job, and soon she’s Vineyard-bound. And as anybody who’s ever gone to the Vineyard or the Cape can predict, the very first person she meets is somebody she already knows: Joanna, the Queen Bee of her class back at Bowdoin. Joanna quickly comments on what a handsome “flirt” Mr. Decker is.

The narrative viewpoint then begins to shift between Lindsey and young Georgie, who is looking for a part-time summer job. Lindsey is getting to know the locals — in particular, handsome Brian Fitzgerald, who later becomes an object of some fascination as well for Georgie, who’s desperate to grow up.

The stage is thus very neatly set for a sweet, sun-drenched summer-on-the-Vineyard novel but Ms. Spiro has other, darker ideas in mind. The combined forces of lust, envy, conspiratorial scheming and townie resentment are churning just under the surface at all times, culminating in an incident at a lighthouse that will reverberate in the lives of both Lindsey and Georgie for the next decade. The book’s timeline shifts forward a decade; Georgie is in therapy and Lindsey has been working at an art gallery for a decade. There is personal and emotional wreckage between them that needs courage and self-honesty to clear away.

Crucially, Lindsey has changed. Thinking back across the decade, she reflects on what might have been if she had gone back to Maryland and stayed there. “She would have met some local guy, married, and had kids before she was thirty. She would have had an unremarkable life.”

Instead, her summer on the Vineyard changed the entire trajectory of her life — not just professionally but personally (“that summer, she learned to lie”). The trauma at the lighthouse changed her fundamentally, and readers finish out the book wondering if things can ever be made right again.