West Country dairy farmer Mark Purdey took on the Ministry of Agriculture in the High Court in 1985 and won his case against the use of organo-phosphates to control warble fly in cattle. This film includes disturbing testimony from some of the many who contacted him with fears that they had been poisoned by 'ops'. He is also strongly supported by the Conservative Chairman of the House of Commons Agriculture Committee Sir Richard Body, who attacks the inordinate influence of the agrochemical industry.