Approaching its bicentenary, traditional tweed clothing company the House of Macpherson has proudly not updated with the times. Its cloth is still spun in the traditional manner by more than seven hundred individual weavers working from their croft homes on the far-flung Scottish islands, whilst its prestigious central Edinburgh office is piled with dust-covered, leather-bound ledgers crammed with financial figures and measurements. Resolutely a family firm, the death of old, stereotypically dour Mr Macpherson leaves the company - and its employees - in the hands of his son, the very jolly Eton-educated Robert.

Largely raised by his prestigious schoolmasters in the south of England, however, Robert means well but sadly lacks both his father's business instinct and intrinsic understanding of their industry and product. Travelling back to Scotland after a long sojourn overseas, chance sees him meet and quickly become beguiled by an American, Angela Barrows, a business consultant specialising in efficiency improvements. She is as enthusiastic as he is about the Macpherson line, having the opportunity to not merely streamline, but modernise company practises that show little sign of having changed since the company's founding.

The largely elderly, job-for-life staff of Macpherson are initially intrigued by her arrival and pleased by her enthusiasm, but soon quickly alarmed: redecorating Robert's office in a resolutely modern, angular, white-washed style may be one thing, but introducing electronic adding machines, inter-office telecommunications equipment, and a range of other 'improvements', are quite another.

For Mr Martin in particular, the firm's senior accounting clerk, these changes are cause for considerable alarm. Fiercely loyal to firm and family, he trusts Robert's judgement and tries not to openly object, but when Barrows begins pushing ahead with plans to make most of the staff redundant, move all their manufacturing to a single, modern, purpose-built factory, and - worst of all - switch from traditional, woollen tweed to the use of synthetic fibre, he begins a one-man campaign of insurrection.

As battle lines are drawn between Scotland and America, man and woman, ancient and modern, Martin enacts his war of small-scale sabotage with efficiency of which Barrows would surely be proud - but when she uses her feminine wiles to dissuade Robert from rolling back the changes, and indeed to press ahead with more, Mr Martin gets murder in mind...