Yorkshire policeman Ron Craven sees his daughter Emma gunned down in front of him. His grief leads him to investigate and he learns of her activities as a radical environmental activist.

Craven's investigation leads him to Emma's boyfriend and to American CIA agent Darius Jedburgh as it becomes apparent that Emma's activities were far from innocent-- and known to the government.

The police close in on their prime suspect for Emma's murder but Craven, now aware of her activities, is convinced that his colleagues are on the wrong track.

Craven confronts Emma's killer but is shot. Suffering from an apparent breakdown, he becomes determined to gain access to Northmoor nuclear plant.

Jedburgh heads to Scotland with the stolen plutonium while Craven awaits the inevitable end.