A killing shocks the erotic film underworld in a mystery featuring Mike Mc Call, the political troubleshooter introduced in The Campus Murders. The film is called The Wild Nymph, and it may be the finest pornographic movie ever made. A relic of the 1950s, when erotic cinema was more artistic than smutty, it was filmed on a shoestring budget by the enigmatic genius Sol Dahlman. But 20 years later, the film has been forgotten and Dahlman has become a recluse. Finding him will be a deadly proposition.   A Hollywood producer comes to the state capital in search of Dahlman, hoping to capitalize on pornography’s growing mainstream acceptance. He meets Mike Mc Call, the governor’s top troubleshooter, whose only interest in pornography is in keeping women’s lib protestors from picketing the theaters. When Dahlman is found dead, it falls to Mc Call to stop the bloodshed. Sex can be controversial, but murder is always taboo.