BBC thriller about a man whose search for the truth about his brother's death catapults him into an international conspiracy, and a passionate love affair. When the reclusive Stephen Ezard (Benedict Cumberbatch) returns to London for the funeral of his brother Michael (Max Beesley), an aid worker killed by a landmine, he feels like a stranger in his own country. Britain has been transformed into a security state after a major terrorist attack, ID cards are strictly enforced and every citizen's movement is watched so the government can catch the terrorists before they strike again. After four years abroad, Stephen is confused and vulnerable and doesn't know who he can trust. A pawn in a mysterious conspiracy, he discovers to his cost just how far the country will go to protect its people.