An Irish washerwoman's daughter falls in love with one of America's most eligible bachelors, much to the dismay of the girl's parents -- and the young doctor's newly acquired fiancée! Events come to a head at the charity masked ball, which the two girls happen to attend in very similar costumes, thanks to the largesse of Molly's benevolent "fairy godfather"; Molly is mistaken for her rival, much to the indignation both of her working-class would-be suitor and the doctor's would-be bride. However, the repercussions that follow serve only to thrust her into her dream man's arms, and all looks set for a fairytale ending... until the disgruntled rival finds a way to get back at Molly through her family...