Stanley and Livingstone Colonel Grimes tells two peace commissioners sent from Washington DC that he cannot permit them to try to contact the Indians of the Wyoming Territory of 1870, as it would be suicidal, only to have Stanley emerge from the wilderness, escorted by a band of the natives and his guide, Jeff Slocum (Walter Brennan). When Stanley returns to New York City, his employer, "New York Herald" publisher James Gordon Bennett, Jr., gives him another near-impossible assignment. The "London Globe" has announced that an expedition headed by Gareth Tyce (Richard Greene), the son of the "Globe"s publisher, Lord Tyce (Charles Coburn),
Stanley and Livingstone has verified that world-renowned missionary David Livingstone is dead. Bennett does not believe it, and would relish embarrassing his rival by proving the story wrong. It is a daunting task, searching the mostly unmapped interior of the "dark continent" for one man, but Stanley accepts the challenge. On the boat trip to Zanzibar, Stanley makes a very unfavorable impression on fellow passenger Lord Tyce. Stanley meets Eve Kingsley (Nancy Kelly) and her father, John Kingsley (Henry Travers), the temporary head of the British authorities in Zanzibar. Eve has been seeing Gareth Tyce, recovering from his ordeal, in the hope of