On the Fourth of July in 1867, the Union Pacific Railroad announced plans to expand their line into the remote mountains of Dakota Territory. They chose a site near Crow Creek Crossing to be their headquarters and named it Cheyenne. Almost immediately, new residents began to arrive: dreamers and schemers, drifters and grifters, good folks and bad. The owners of Union Pacific knew there'd be problems. Between settling disputes, laying down tracks, and keeping the peace, they'd need a troubleshooter. A reliable man of steely resolve. A concealed weapon . . .

His name is Derringer. Like the gun.

Arriving by cattle car with two of his beloved horses, Jesse Derringer is not your typical railroad employee. With the eyes of a scout, he looks for trouble before it becomes a problem for the construction crews—and sometimes starts trouble himself. Usually he handles hot-tempered troublemakers with a cool head and steady hand. But then there are problems that are more complicated and it's Derringer's job to defuse them—before they ignite a full-blown bloodbath.

Jesse Derringer is about to learn the true definition of trouble-shooting.