The story of the voyage that changed human understanding forever. In 1831, Charles Darwin set out on an expedition to South America, brought along as a gentleman companion for Captain Robert FitzRoy. Initially conceived as a Christian mission, the voyage would change drastically as the Beagle sailed through the Pacific, with Darwin's observations becoming the building blocks of his revolutionary theory of evolution. This theory put the rational, scientific Darwin at odds with the deeply religious FitzRoy, who would go on to publicly denigrate Darwin and his heretic ideas. Unbeknownst to FitzRoy, his young friend's intellect would one day tower over the voyage and his own career. A fascinating look at this seminal journey and the differences between Darwin and FitzRoy, which captures the tension of the Victorian period - an age torn between religious certainty and scientific doubt.