As produced by the BBC, the release presents three back to back docudramas that recreate the excitement and suspense of history's most courageous explorers, via sweeping on-camera reenactments. The first segment follows Meriweather Lewis and William Clark, circa 1804, as they hearken out of Missouri and comb the wilderness for a trade route to the Pacific; the second cuts back to the 18th century to observe German naturalist Alexander von Humboldt as he embarks from Europe to the then-uncharted continent of South America and attempts to systematically document the plant and animal life of that region; and the third drama observes Antarctic explorer Ernest Shackleton as he and his crew spend two years struggling to survive at all costs amid the polar regions. David Yelland, Kal Weber and Christopher Eccleston co-star .