Mrs.  Callahan and Mrs.  Murphy, who live on opposite sides of a narrow alley in the tenement district, are quarrelsome friends, although their children, Ellen and Dan, are in love.

Dan becomes involved with a gang of bootleggers and disappears.  Ellen, meanwhile, gives birth to a child which her mother contrives to adopt without knowledge of its origin.  When Dan returns, the couple confesses to having been secretly married.

The Callahans and Murphys once again resume their happy existence, with the mothers arguing over the baby's family resemblance.