The story opens with the dramatic arrival of John Delancy Curtis in New York after ten years abroad, brimming with an expatriate's intense longing for the city. Almost immediately, he is thrust into a vortex of violence and mystery when he witnesses a murder outside his hotel and accidentally takes the victim's overcoat. Inside the coat, he discovers a marriage license bearing the names of a French music-master and Lady Hermione Grandison, a young British aristocrat who has fled her home to escape a forced marriage with a detested Hungarian prince. Compelled by a chivalric impulse and a strange sequence of chances, Curtis seeks out the terrified girl and impulsively offers to marry her himself to save her from her persecutors.
As the night unfolds, they navigate a labyrinth of desperate maneuvers, chased by the girl's ruthless father and rival. The narrative weaves a complex web of deceit, involving hidden motives, secret documents, and dangerous conspiracies orchestrated by the shadowy conspirators from Europe. Curtis must balance his sudden devotion to his new wife with the harsh realities of a city gripped by crime and confusion, all while unravelling the true threads behind the bloody attack that started it all. The romantic tension heightens as the fake marriage begins to feel remarkably real, leading toward a tense and uncertain dawn.
