The Death of Boris Berezovsky

On March 23, 2013, Boris Berezovsky, the once powerful Russian oligarch who helped bring Vladimir Put to power, was found dead in home in Ascot, England, an as yet "unexplained death," according to British authorities. 
  Some seven years earlier, on January 23, 2006,  Berezovsky had been the toast of London, or Londongrad as he called it, holding  his 60th black-tie birthday party at Blenheim Palace, Winston Churchill's birthplace. In the center of the room was an ice sculpture representing St. Basil's Cathedral on Red Square, coated with mounds of belugi caviar. At one table was Alexander Litvinenko, Andrei Lugovoi, and Akhmed Zakayev. They all had been born in the former Soviet Union and they had all been in prison, and, under Berezovsky's aegis, they would  engage in covert intelligence operations in Russia. Britain, and Spain.  Berezovsky's stated goal was to overthrow the Putin regime, explaining in a 2007 interview with The Guardian,"It isn't possible to change this [Putin] regime through democratic means. There can be no change without force, pressure." Asked by the reporter if he was effectively fomenting a revolution, he said: "You are absolutely correct." Ten months later, these men, and Berezovsky's most private office, would be exposed to the rare radioactive isotope, Polonium-210, that had been smuggled into London.  Despite a surfeit of speculation, there is no satisfactory explanation how the Polonium 210, which can be used as a trigger in an early stage nuclear weapon, got to London.  For my take on this mystery, based on my extensive interviews in Moscow and London, see "The Case of The Radioactive Corpse" in my book The Annals of Unsolved Crimes.