The 1999 Good Friday Agreement the British and American governments have put together does not meet the approval of one IRA dissident cell.

They feel they have been sold out and their current lifestyle, derived from running drug dealing and protection rackets will be badly effected. Their leader Michael Caldwell decides to compensate fpr their loss of income by planning an assault on the Scotch Whisky industry unless they meet his demands for a £20m ransom. He plans on carrying out his threat by using a sympathiser to his cause who places semtex explosives in whisky barrels which aer then stored in warehouses in different parts of Scotland

Operation Large Scotch covers the period 1982-2000 which was at the height of the troubles and how a botched British commando ambush resulted in seven deathes and acting as as a catalyst for Mhairi McClure, whose fiance' was killed in the raid to join the IRA.

Both Police Scotland and MI5 are alerted by the terrorists to their demands but unable to locate where the threat will come from until John Johnston, who has fled to South Africa after witnessing the ambush years previously nforms Mossad the Israeli secret service. MI5 must now intervene and stop the possibility of many innocent civilians being killed -but will they be in time?