April 1943 - A Mitsubishi transport plane, carrying Admiral Isoruku Yamamoto, architect of the Japanese attack on Pearl Harbor, plunges from the sky over the island of Bougainville. In a document case chained to his wrist is the greatest secret of the Second World War. . . December 2011 - Art recovery expert Jamie Saintclair is offered a lucrative commission: he has been tasked to find the preserved head of a Solomon Island warrior, missing from a German museum since 1945? The search takes Jamie from Berlin to Tokyo and with every turn the significance of the Bougainville skull becomes ever greater. Soon he realises he's become involved in something much more important than finding a lost piece of history?