A little over a century ago, at the height of European colonial expansion in Africa, the British undertook a trans-Kenya railroad from Mombasa on the Indian Ocean to Lake Victoria. One hundred and thirty miles in, at what is now the Tsavo National Park, one of the world's largest wildlife preserves, nature struck back in the form of two male lions who began to systematically hunt, kill, and devour railroad workers, claiming 135 lives. The...