Vivian Kelly has finally created a home and a family at the glamorous speakeasy known as The Nightingale. When a stranger from Chicago shows up there looking to settle old scores, Vivian and the Nightingale's owner, the mysterious and alluring Honor Huxley, send him packing. They soon discover, though, that the stranger was just a warning. Slowly, the people who have made The Nightingale their home realize that someone is following them --- and won’t stop until they unravel a mystery that’s been cold for years: a missing girl, a boy out for revenge, and a truck full of cash that disappeared in a job gone horribly wrong. Vivian just wants to protect the people she loves and is willing to dig into the dirt of the past to make it happen. But she has more to lose than ever before.

By day, Vivian Kelly is a respectable shop assistant, delivering luxurious dresses to New York City's wealthy and elite. At night, she joins the madcap revelry of New York’s underworld, serving illegal drinks and dancing into the morning at a secretive, back-alley speakeasy known as the Nightingale. She's found, if not love, then something like it with her bootlegger sweetheart, Leo, even if she can't quite forget the allure of the Nightingale's sultry owner, Honor Huxley. Then the husband of a wealthy client is discovered dead in his study, and Vivian was the last known person to see him alive. The police and the press are both eager to name a culprit, and Vivian finds herself the primary suspect.

Life as a working-class girl in Prohibition-era New York isn’t safe or easy. But Vivian Kelly has a new job at the Nightingale, an underground speakeasy. Things are finally looking up for her and her sister, Florence...until the night Vivian learns that her friend Bea's uncle, a bouncer at the Nightingale, has died. His death is ruled a suicide, but Bea isn’t so convinced. She knew her uncle was keeping a secret: a payoff from a mob boss that was going to take him out of the tenements and into a better life. Now, the money is missing. Vivian and Bea uncover more than they expected when rumors surface of a mysterious letter writer who's blackmailing Vivian's poorest neighbors for their most valuable possessions, threatening poison if they don't comply.

New York, 1924. Vivian Kelly's days are filled with drudgery, from the tenement lodging she shares with her sister to the dress shop where she sews for hours every day. But at night, she escapes to The Nightingale, an underground dance hall where illegal liquor flows and the band plays the Charleston with reckless excitement. With a bartender willing to slip her a free glass of champagne and friends who know the owner, Vivian can lose herself in the music. But then she discovers a body behind the club. With too many people assuming she knows more about the crime than she does, Vivian finds herself caught between the dangers of New York's underground and the world of the city's wealthy and careless.