Act One

We meet the Tobin family outside of their shack in Hannibal, Missouri. The time is early 1900s. Molly, a headstrong tomboy, is wrestling with her three younger brothers. The village priest enters and expresses some concern with Molly's freeness with the boys but Shamus Tobin, the clan's patriarch, assures him that everything is as it should be. Molly confirms this and we begin to understand just what an inimitable force she is ("I Ain't Down Yet"). After the colorful display, the priest leaves and Shamus puts the boys to work. He leads them in an old-fashioned Irish drinking song ("Belly Up To The Bar, Boys").

Weeks later, we are now in the small mining town of Leadville, Colorado which is in the middle of a boom. Outside the Saddle Rock Saloon, we see several drunk miners with their giggling prostitutes. Up the boardwalk, Johnny Brown struts into the scene ("Colorado, My Home").

A few more weeks later, we are inside the Saddle Rock Saloon. The brawling miners engage in what seems to be a typical fracas. As they leave to find some racier entertainment at The Nugget, Molly enters the saloon with a 'Boy Wanted' sign in her hand; she intends to apply for the job. Although bar owner Christmas Morgan is reluctant to give the job to a girl, Molly uses her spitfire charm to convince him to take a chance. Molly spends all night trying to figure out how to play the piano. At sunrise, the miners come in to find Molly banging away on the keys and jubilantly singing "Belly Up To The Bar, Boys." They all join in. Raucous dancing ensues and Molly is thrilled to be at the center of it all. The miners and prostitutes in the saloon leave as they hear that Old Davy has just panned a huge nugget; Johnny slips in and watches Molly. He grabs her from behind and she responds like an exploding firecracker. Christmas formally introduces them and Johnny confidently declares that she's the girl he's going to marry.

Three weeks later, outside the Saddle Rock. The locals are happily parading along Main Street. Johnny continues to flirt with Molly, but she has made it perfectly clear to him that she won't settle. For her, money is the answer to her prayers and continues to reject his earnest advances. Johnny, however, won't take no for an answer ("I've Already Started In").

About a month later, Molly and Johnny arrive at Johnny's modest log cabin. Molly has finally agreed to visit Johnny's small abode. She is not terribly impressed, even though Johnny says that he built it for her. However, when Johnny shows her the extra room he built for her Pa, she is clearly touched. Johnny goes on to promise her that she will have whatever she wants, whatever she needs, whatever she asks for ("I'll Never Say No"). Still not convinced, Molly wanders into the bedroom and is entranced by the bed ("My Own Brass Bed"). Finally softened, she agrees to marry Johnny.

Three weeks later, the townspeople are reflecting on the beautiful wedding. Christmas is on his way to visit the newlyweds. To his shock, Molly confides that she hasn't seen her husband since they got married. He has mysteriously vanished and she is heartbroken. Christmas agrees to give her old job back. Night falls as Molly softly weeps on the porch. Suddenly, Johnny returns. Molly is furious, but she lets her husband talk. Johnny explains that he felt guilty about not getting her a wedding present, so he went off with the boys, found a claim and sold it to some men from New York for three thousand dollars. Molly is ecstatic. Johnny takes off for the bar and while he is gone, Molly finds a hiding place for the money in the pot-bellied stove. Johnny returns from his swim with the boys. Shivering and still quite drunk, he lights the stove to warm up. Molly wakes to the smell of money burning. She is absolutely horrified, but Johnny assures her that there's plenty more money to be made.

Six months later, we are in Denver. Manicured lawns line Pennsylvania Avenue, the grandest street in the city. Three policeman are walking the beat ("The Denver Police"). We shift to the terrace of Mrs. McGlone's mansion, where we meet Denver's elite. They speak of the desired location for a new cathedral - Pennsylvania Avenue has been all bought up by the Browns, who have seemingly relocated to Denver with considerable wealth. Molly bursts onto the terrace - she is dressed to the teeth, bejeweled to extreme. She introduces herself to the hordes of Denver's upper crust and says that they need no introduction ("Bea-u-tiful People of Denver"). Mrs. McGlone is a bit undone by the brashness of her uninvited guest but does her best to compose herself.

Johnny is extremely uncomfortable in this world, but Molly doesn't notice. Upon meeting the Monsignor, Molly spontaneously donates five thousand dollars to the new church and challenges her husband to put in another ten. Evidently, Mrs. McGlone has not made her contribution yet. Molly takes it upon herself to see that this is remedied by passing around Johnny's hat and leading the whole crowd in a rollicking revival ("Are You Sure?"). The Monsignor is very impressed; he praises Molly. Even Mrs. McGlone is in awe, but she won't have her thunder stolen any further. Through her attendant she relays that there is no room at the table for two more people. The Browns say good night to everyone else, and graciously leave the premises.

One month later, we are in the garish Red Parlor of the Browns' Denver mansion. It is the evening of their housewarming part and the Monsignor is the only guest. Molly is at a loss for why nobody else showed, seeing as she invited the whole town. The Monsignor tells Molly that her personality is too strong for a young society to handle. The Monsignor suggests the Browns go to Europe for some culture and grooming. Johnny wants to return to Leadville where they belong but Molly refuses.

Act Two

The second act opens in Paris at the Browns' salon. It is a spring afternoon, years later. An international set of Princes and Princesses file in to throw Molly a surprise birthday party ("Happy Birthday, Mrs. J.J. Brown"). Molly talks to her royal European friends, admitting that back in the states she's seen as vulgar, but in France she's seen as entertaining. She loves the opportunity to learn about everything, especially languages ("Bon Jour [The Language Song]"). However, even as the darling of royalty, she is unable to forget how she had been snubbed in Colorado. Determined to avenge herself, she invites all her highborn friends to come home to America with her, where Molly plans to throw another party. Johnny is elated to go back to Colorado ("If I Knew").

Months later, in the Browns' Denver mansion, everyone is setting up for the big party. Shamus, Molly's father, questions if his daughter is struggling to hold her marriage together. Then, Molly and Johnny get into a fight over Johnny inviting the boys from the Saddle Rock Saloon. Molly stubbornly refuses to get dressed until Johnny un-invites them ("Chick-A-Pen"). Later in the evening, Molly greets her guests. This time the cream of Colorado society shows up at the party; they are impressed by the distinguished foreign visitors. However, some of the less desirable elements in Colorado break in on Molly's party. One of Johnny's friends punches a Denver socialite after he insults Molly's piano-playing. A rowdy free-for-all ensues, and the party disintegrates into a fiasco.

Following the drama, Molly and Johnny decide to separate but Johnny refuses to get a divorce because his Irish-Catholic religion forbids it. Johnny drowns his sorrows at the Saddle Rock Saloon and laments his failed relationship ("Keep-a-Hoppin'/Leadville Johnny Brown [Soliloquy]"). Molly, meanwhile, decides to go back to Europe in the company of the Prince de Long to try and escape her sorrows ("Up Where The People Are").

In Monte Carlo, Prince de Long begs Molly to divorce Johnny and marry him ("Dolce Far Niente"). Molly hesitates because she has not forgotten Johnny and is still madly in love with him ("I May Never Fall in Love With You"). The memory of Johnny, and her desire to be with him, sends her back home. She books passage for the Titanic on its maiden voyage.

When the Titanic collides with an iceberg on April 14, 1912, sending almost fifteen-hundred passengers to their death, Molly somehow manages to survive, being one of the seven hundred carried to safety in lifeboats. Back in Colorado, she finds Johnny waiting for her and her friends are ready to salute her courage ("I Ain't Down Yet [Finale]").