Harmful Intent, Cook's longest novel, is better integrated than his earlier works with episodes unfolding in a smoothly connected fashion. Cook employs a third person narration and labels his chapters by day and date. Cook avoids moralizing about the issues he raises, and indeed the novel closes without a clear resolution of who is responsible — morally — for the murders.

Cook's novels reflect issues currently under public debate. Mortal Fear (1988) anticipates the government's approval of increased research into gene therapy and the use of recombinant DNA, but focuses more on a horrifying solution to the problem of high-cost medicine in an age of dwindling finances. The growth of HMOs, the allocation of health care dollars in an era of expensive technology, and the high demand for care are major concerns of the novel. Costly technology can keep some patients alive for long periods, but should these expensive resources be allocated for persons who deliberately ruin their health by overeating and smoking, for example, or are they better spent on those who are sick through no fault of their own and can get better?

The HMOs and prepaid health plans that have sprung up only make money if people stay healthy; those who persist in high-risk, self-destructive activities will drain the organization. And in this novel, when money becomes the deciding factor, little heed is paid to ethics. Mortal Fear focuses on health care as big business and on administrators who are fixated on the "bottom line." What happens when researchers discover scientific and medical secrets that can be used to harm rather than to heal? Are there enough controls to keep this possibility in check? Who determines the applications of such research?

In Mortal Fear, while diligently searching for a way to keep people young, Dr. Alvin Hayes discovers how to make them age and die quickly. The executives of the Good Health Plan Clinic for which Hayes works decide that his discovery can keep the clinic profitable; they sell expensive, prepaid health plans to corporations whose executives come in for annual physicals. At that time their health is evaluated for risk behaviors. Hospital administrators then use Hayes's discovery to murder executives whose prognosis, based on lifestyle, suggests they will need expensive therapy in the future. Thus, the clinic profits by never having to provide expensive services to its clients.

Dr. Alvin Hayes is a brilliant researcher at Good Health Plan Clinic working on gene therapy and growth factors that could benefit cancer treatment or extend life. But his research leads to the discovery of how to accelerate aging and death. He is murdered by his own discovery so that the clinic's administrators can use it for their own ends.

The novel's protagonist. Dr. Jason Howard, a middle-aged physician, arrives to work at the clinic in an attempt to climb out of a depression caused by his wife's death. Recently bereaved, he is affected by the increasing number of deaths among his patients soon after he has given them clean bills-of-health at their annual check-ups. Compassion for his patients, a professional dedication to life, an increasing sense of incompetency, and an aroused curiosity (after Dr. Hayes dies in his arms) — all impel Dr. Howard to search for the cause of these deaths.

Attractive hospital administrator Shirley Montgomery comforts Howard over the loss of his patients. Her interest, however, is feigned; she is trying to keep him from finding out the truth behind the unexpected deaths. Dr. Hayes's recent lover, Carol Danner, is a young woman who studies at Harvard at day and dances topless at night. Her character seems designed to bring the Boston demi-mode into the novel. She is a woman of "low morals" but with a heart (and mind) of gold, who rescues Howard from his depression.