The Secret of One Night tells about the life and love of three young women: Cyril Hendrick, daughter of a handsome, beggar, bastard; her best friend Sidney Owenson, a naive heiress; and Dolly De Courcy, an energetic actress. Both Cyril and Sidney are engaged, although everything is not as it seems in any case. Sydneys gold miner is stupefied by Dolly, and Cyril is satisfied with her aunt, whom Cyril calls the most humble, vicious old woman on earth. The Secret of One Night in the title refers to the disappearance of the groom Sidney the day before her wedding, but did he run away with Dolly or was he killed?