One of the last bills signed by President Lincoln authorizes pushing the Union Pacific Railroad across the wilderness to California. But financial opportunist Asa Barrows hopes to profit from obstructing it. Chief troubleshooter Jeff Butler has his hands full fighting Barrows' agent, gambler Sid Campeau; Campeau's partner Dick Allen is Jeff's war buddy and rival suitor for engineer's daughter Molly Monahan. Who will survive the effort to push the railroad through at any cost?
Truck driver Mike Lambert is a down-and-out mining engineer searching for a job. When his rig breaks down in a small town, he happens upon a venomous seductress. When her boyfriend robs a bank, they intend to frame Lambert.
After completing military service, Walter Gulick takes a job as a sparring partner at a gym, the owner of which sees potential in Walter as a professional fighter—and takes him under his wing.