In the mid-19th century, Senator William J. Tadlock leads a group of settlers overland in a quest to start a new settlement in the Western US. Tadlock is a highly principled and demanding taskmaster who is as hard on himself as he is on those who have joined his wagon train. He clashes with one of the new settlers, Lije Evans, who doesn't quite appreciate Tadlock's ways. Along the way, the families must face death and heartbreak and a sampling of frontier justice when one of them accidentally kills a young Indian boy.

作为一部修正主义西部片，“道克”是弗兰克·佩里（Frank Perry）试图准确描绘道克·霍利迪（Doc Holliday）、怀亚特·厄普（Wyatt Earp）的生活和人物，以及由斯泰西·基奇（Stacy Keach）、费·唐纳薇（Faye Dunaway）和哈里斯·玉林（Harris Yulin）主演的如今在墓碑镇（Town of Tombstone）发生的传奇故事。