When The Det seize a huge terrorist arms shipment, the IRA's master tactician, Cillian Rainey, begins a vicious war against Colonel Mabbitt's secret unit. When Mabbitt discovers Rainey's most daring and terrifying plan yet, Michael Prentiss suddenly finds himself returning to the clandestine world of secret intelligence. Can Prentiss, Jordan and Mabbitt prevent the unthinkable in a deadly race against time?