On the Edge is an unflinchingly intimate portrayal of a man troubled by his past, the stress of a passionate love relationship with his young wife, and the pressures of his morally ambiguous job. Through Poverman's protagonist Frank August, we are exposed to a searingly candid picture of a legal investigator and the criminal justice system itself.

Having failed the California bar exam, Frank August has become an investigator in San Francisco by default. When a lawyer offers him a drug case at his client's request, Frank is severely compromised; no one knows that the client and Frank have an old and complex friendship. As Frank goes deeper into the case, he finds himself confronted by his unresolved relationship with his dead father, his drinking, and his wife.

He will ultimately be pushed to make a decision which will call all of his relationships into play, and test his concepts and bonds of loyalty and friendship.