As narrated by Hal Holbrook, Dayton Duncan's script explicates the agenda presented by Thomas Jefferson to Meriwether Lewis and William Clark, placing it in the context of the young country's gamble in Jefferson's Louisiana Purchase, and the expedition's goals for opening the West. While preserving the heroic scale of the undertaking, Burns also finds time to delve into the politics of the venture and the disparate personalities of the two explorers; in particular, Duncan and Burns look at the career of Lewis, the presidential protege, his moody demeanor, and his untimely death. The film also looks beyond its titular leaders to examine the personalities of their corps of soldiers, their boatmen, and the Indians they met and depended on, most notably their female Shosone guide, Sacagawea. --Sam Sutherland