Substance D is the most dangerous drug on the market. It destroys the link between the brain's two hemispheres, leading eventually to irreversible brain damage. Undercover narcotics agent Bob Arctor is trying to find a lead to the source of supply, but is soon as dependent as the other addicts.

Substance D is the most dangerous drug on the market. It destroys the link between the brain's two hemispheres, leading eventually to irreversible brain damage. Undercover narcotics agent Bob Arctor is trying to find a lead to the source of supply, but is soon as dependent as the other addicts.