In 1985, off the northwest coast of England, an audacious hijacking by Irish Protestant paramilitaries culminates in the disappearance of one hundred million pounds of gold bullion. En route to Ireland, the seagoing barge Irish Rose capsizes and sinks under mysterious circumstances. Michael Ryan, the mastermind behind the plot, his niece Kathleen, and the mysterious Martin Keogh survive the disaster. Everyone and everything else on board disappear beneath the waves with the ship. Ten years later, as the peace process falters in Ireland, the American president gets information about the Irish Rose and her cargo; it may be at the disposal of terrorist powers, who intend to use it to finance an Irish civil war. Inspired by the adage, "set a thief to catch a thief, " the president and the English prime minister agree: only Sean Dillon, once the most feared IRA enforcer, now in the employ of British Intelligence, can avert disaster.