After
buying suits on credit and sneaking drinks from the medicine cabinet
of their scientist friend, "Doc" Powers, coal miners Cash Evans and
Charles "Pittsburgh" Markham go to a vaudeville house, where a
promoter is offering $500 to any man who can last three minutes with
boxer Killer Kane. Just as they are about to enter the
theater, they meet beautiful Josie Winters. Pittsburgh tricks
Cash into taking the boxing challenge, and a riot breaks out when
the promoter tries to sneak out of the theater after Cash defeats
Kane. The riot, however, is interrupted by news of a cave-in.
Cash, Pittsburgh and Josie rush to the mine, where
they learn that Doc is trapped with the injured miners. After
almost being killed himself in the rescue, Pittsburgh learns that
Josie worked in the mines as a child and her father was killed
there. Although he brags that he is going to be a "big-shot"
someday, Josie accuses him of being all talk and no action.
She later challenges Pittsburgh to make good on his
boast, so he and Cash quit their mining jobs, then arrange a meeting
with Morgan Prentiss of Prentiss Steel, where they offer to sell the
steel magnate coal for three dollars a ton less than the current
price. Morgan agrees to a contract with the two, on the
condition that Pittsburgh and Cash raise $250,000. Though
neither has the four dollars necessary to pay their back rent, they
forge Morgan's name onto the contract, which gets them the necessary
bank loan.
With Doc and Josie as their partners, Pittsburgh and
Cash soon become a great success. That success, however, goes to
Pittsburgh's head, as he forgets his promises to the union miners
and begins courting Morgan's daughter Shannon. When Josie,
Cash and Doc plan a surprise birthday party for Pittsburgh, he fails
to come home, having spent the evening with Shannon. That
night, Josie admits her love to Pittsburgh, then tells him that they
are finished. Cash tells Pittsburgh that he is in love with
Josie, and that he now plans to court her.
Pittsburgh and Shannon are soon married. On
their wedding night, however, Pittsburgh goes to see Josie and tells
her that she will always be his. Josie refuses his advances,
however, and orders him to leave.
The bitter Pittsburgh becomes a ruthless businessman,
taking over both the Wilson mine and Prentiss Steel. Shannon
later demands a divorce from her cruel husband when, during a party
held in their home, his infatuation with Josie is made clear to all,
but he refuses to cooperate. After Pittsburgh announces that
he going to close down Doc's medical research lab, an irate Cash
quits the partnership and sells out his shares to Pittsburgh.
After the two men go down a mine shaft to fight, Josie is critically
injured when she attempts to stop them. At the hospital, Cash
tells Pittsburgh that he is no good, and that his old friends never
want to see him again. The repentant Pittsburgh goes home to
Shannon in an attempt to make amends, but she refuses him.
Later, Morgan keeps his promise to avenge his
betrayed daughter by bankrupting Pittsburgh. At the outbreak
of World War II, the broken Pittsburgh learns humility and goes back
to work as a steel mill worker under the name "Charles Ellis."
The factory Pittsburgh works for is owned by Cash and, when Cash
decides to fire the unproductive production manager, union boss Joe
Malneck recommends "Ellis" for the position. Cash and
Pittsburgh immediately begin to argue, but then Josie arrives and
convinces them that they must put aside their personal grievances
and order to work together for the good of the country. With
industry and labor working together, Markham and Evans Industries
soon becomes a leader in defense, building an "arsenal of
democracy."