 Subtitled "A legendary problem and the battle over who solved it", the article concentrates on the human drama of the story, especially the discussion on who contributed how much to the proof of the Poincaré conjecture.Interwoven with the article is an interview with the reclusive mathematician Grigori Perelman, whom the authors tracked down to the St. Petersburg apartment he shares with his mother, as well as interviews with many mathematicians.The article describes Perelman's disillusionment with and withdrawal from the mathematical community and paints an unflattering portrait of the 1982 Fields Medalist, Shing-Tung Yau.