Charles Pike, a wealthy and naive heir to a brewing fortune, meets Jean Harrington, a beautiful and cunning con artist, aboard a luxury cruise liner. Jean, along with her father Colonel Harrington, plans to swindle Charles out of a substantial amount of money. Jean seduces Charles and easily wins his affections. Despite warnings from his suspicious bodyguard Muggsy, Charles falls deeply in love with Jean. However, when Charles discovers Jean's true identity as a card sharp, he is heartbroken and leaves her, vowing never to see her again.

Determined to exact revenge on Charles for breaking her heart, Jean concocts an elaborate plan to re-enter his life under a new guise. She transforms herself into the sophisticated Lady Eve Sidwich, claiming to be an English aristocrat. Charles, completely oblivious to her true identity, once again becomes enchanted by the woman he believes to be Lady Eve. As Jean's scheme progresses, it becomes increasingly uncertain whether she will succeed in her mission or if genuine feelings for Charles will compromise her plans. Ultimately, their tumultuous relationship tests the boundaries between deception and love.