Deadline at Dawn by Cornell Woolrich
When Quinn first meets Bricky, she's working as a partner-for-hire at a dancehall and he's struggling to shake the anxiety of his guilty conscience. Earlier that day, the young man took advantage of a found key and used it to rob a stranger's home. Now, with the purloined money in his pocket, Quinn is unable to escape the memory of his wrongdoing--and not even a night spent dancing is enough to silence his nagging thoughts.
When the dancehall closes, he and Bricky--linked, after many intimate hours, by a budding romance--return to the scene of the crime intending to restore the stolen fortune and begin a new life together, only to discover, upon arrival, that the owner of the property has been murdered. There's evidence present that easily links Quinn to the crime, and he expects that, as soon as day breaks and the authorities learn of the gruesome scene, he will be arrested straight away. Which means that he and Bricky have only a few short hours to find the true killer and clear Quinn's name for good.
What begins as a romance soon turns into a nightmare, as this young couple trek through the dark underbelly of old New York in a desperate race for salvation. Twisty, turny, and breathlessly told, Deadline at Dawn is an exemplary tale from the "supreme master of suspense" (New York Times).