When a filmmaker and a British civil servant get caught up in the endgame of the Irish Troubles in 1997, they find themselves crossing borders that are ethical as well as physical and are forced to make lethal choices.

Perdita Burn is a journalist with a track record in political documentary; Daniel Booth a British government press officer with a document to leak - a startling revelation about the Irish Troubles. A bomb explodes in South Armagh and Perdita is shocked to realise it was predicted in Daniel's document, suggesting collusion between some part of the security services and paramilitaries in Northern Ireland. Her attempts to investigate draw her into ever murkier territory, political and personal. Back in London, Daniel realises he's being used as a pawn in the struggle between those who want to bring peace to Ireland and vested interests set on prolonging the war. As the plot darkens, it becomes clear that most of the people in this story are traitors of one kind or another - some deliberately, and perhaps bravely, like Daniel; others drawn gradually over the line.