100 years ago the Anglo-Irish Treaty was signed, bringing to a formal end the Irish War of Independence and ending centuries of British colonial control. During the war members of the IRA were pitted against the Royal Irish Constabulary, the British Army and the notorious Black and Tans and Auxiliaries. It's a story of divided loyalties and the unresolved traumas of war, with resonance today as Britain and Ireland struggle to address the legacy of the more recent violence of the Troubles in Northern Ireland. In an investigation into the fate of one man, James Kane, the River Man, executed by the IRA a century ago, by men he knew and who liked him, Fergal Keane explores some of these issues. Why did they kill him and what were the consequences for his family and his executioners? Producer: John Murphy