Skinner's Festival (1994) – Quintin Jardine

In August each year Edinburgh is filled with thousands of tourists, performers, and enthusiastic spectators who flood into the ancient city for its Festival of the Arts - a display of culture ranging from the highly professional to the rank amateur.
But this year, on the very first day, an explosion rocks a hospitality center at Princes Street, and one man is killed. Assistant Chief Constable Robert Skinner, head of Edinburgh CID, soon establishes that it was no accident.
A few hours later a threatening letter is delivered to the Secretary of State from a group calling itself Fighters for an Independent Scotland, which demands the end of parliamentary union England.
Skinner quickly assembles a team and maintains a news blackout on the terrorists' threat to avoid widespread panic. Every Festival event must now be rigorously checked for security - but the following afternoon an American opera singer becomes the second victim.
As atrocities escalate, Skinner realizes this is no gang of bloodthirsty fanatics, but an international team with access to the most sophisticated armaments and technology. Even though every known agitator in Scotland has been rounded up for questioning, the mayhem continues. And the imminent visit of the Prime Minister provides the police with a nightmare scenario...
But behind this terror campaign lies a hidden agenda, and with the ancient honor of Scotland at stake, Skinner is under pressure to solve the riddle soon.