Christopher Cross, a meek cashier and amateur painter, leads a life of quiet desperation in a loveless marriage. One fateful night, while walking home through the rain after celebrating his 25 years of service with a pocket watch, he intervenes in what appears to be a mugging. He rescues a young woman, Kitty, not realizing the encounter is about to drastically alter the course of his mundane life. Struck by her beauty and apparent vulnerability, Cross falls for Kitty, oblivious to her manipulative and opportunistic nature. In a whirlwind of infatuation, he showers her with gifts and even finances an apartment for her, all while keeping their relationship a secret.

Kitty, along with her deceitful boyfriend Johnny, a small-time con artist, quickly recognizes Cross's infatuation as an opportunity to exploit him for financial gain. They concoct a scheme to milk Cross for all he's worth under the guise of Kitty’s affection for him. As Cross becomes more emotionally entangled with Kitty, he begins to share his dreams and ambitions, revealing his aspirations of becoming a recognized painter. Johnny sees an opportunity in Cross's paintings and hatches a plan to profit from his artwork, further entangling Cross in their web of lies and deceit, setting off a chain of events that threatens to unravel Cross's mundane existence and thrusts him into a world of crime, passion, and desperation.