Great Britain does not negotiate with terrorists. Shock waves are felt throughout the world when members of the IRA hijack the royal yacht Britannia with Queen Elizabeth and Prince Philip on board, demanding the removal of British troops from Northern Ireland within seven days. With the support of a Middle Eastern terrorist group and a British traitor, the hijackers stand off against British and American naval forces, while the British government agonises over the choice before them. Time is running out fast, and tensions in Belfast, in the British government and among the hijackers quickly reach their limit. As the pressure mounts, British and American special forces come together to pull off a spectacular rescue attempt that has only one chance to succeed.