A man and woman fall in love at first sight, but everyone in their universe tries to keep them apart except one old fool with a sentimental heart.

When she can't support her illegitimate child, an abandoned young woman puts her up for adoption and pursues a career as a torch singer. Years later, she searches for the child she gave up.

In an effort to be able to afford expensive treatment for her gravely ill American husband, a retired German entertainer returns to the cabaret as Blonde Venus and catches the eye of a wealthy politician.

Riley and Donovan, racehorse owners and trainers who have been rivals and enemies for years, seek to befriend Tod Taylor, a jockey, and Ham, a retainer. Tod elects to work for Riley, incurring the enmity of rival jockeys. Riley's daughter, Colleen, sympathizes with Tod and cares for his bruises. Trying to befriend Donovan, Tod wins a match between Riley's colt, Reckless, and Donovan's best horse; and many more victories bolster his confidence. His head is turned by Margie, a come-on girl for Drake, a gambler. She precipitates his dissipation, and Tod is induced to throw the race to avoid a jail sentence.

Nappus sends his grandson north for schooling to shelter him from their community.

Shortly after the United States enters World War I in 1917, a Broadway actress agrees to let a naive soldier court her in order to impress his friends, but a real romance soon begins.

Young Brierly struggles to save his father, Major Brierly, from the clutches of alcohol after the Great War. At the same time, he prepares Major Brierly's horse, which served bravely with the Major at the front, for the Kentucky Derby.