Cook's third-person narrator is omniscient, telling what the characters are thinking but providing little explanation as to how they have come to think that way. Another Cook technique is to casually intersperse key clues with insignificant medical details, keeping the reader's mind churning as it tries to sort things through and find a focus.

Cook's most interesting and oft-used technique is the repetition of allusions to a facility or institution which, shrouded in mystery and surrounded with security against the outside world, seems linked to the ongoing crimes. Both the protagonist and the reader crave to sneak inside, snoop around and finally solve the puzzle.

In Coma, the mysterious facility is the Jefferson Institute, an intensive care facility for comatose patients. Inside, Susan Wheeler discovers that the intensive care is administered by a mainframe computer that continuously monitors each patient's bodily functions, automatically making adjustments to maintain homeostasis. Naked patients are suspended in space by wires strung through their bones, eliminating potential bedsores. The environment is bathed in ultraviolet light to minimize bacterial infections. All these bodies are maintained in a state of readiness — awaiting orders for organs with the right tissue match and price.

In the years since this novel was published, its central concern — the shortage of available transplant organs — has become a growing issue in the media and American legislatures. In Coma, the premise is that demand for organs will so outdistance supply that a black market will develop.

In Coma's scenario, the black market for human organs mimics the more mundane black market for automobile parts: instead of removing needed parts from a brain-dead person — equivalent to a totaled car — the black marketeers render a normal, essentially healthy person permanently comatose in order to fill orders for highly marketable organs. The sabotaged bodies are stripped of hearts, lungs, livers, and kidneys — in the same way parked cars are stripped of radios, batteries, and bumpers — and sold piecemeal to the highest bidders.

The Howard Starks in Robin Cook novels are throwbacks to the deadly mad scientist — often a physician — who recurs in such Nathaniel Hawthorne stories as "The Birthmark" and "Dr. Heidegger's Experiment." In "Rappacini's Daughter," Hawthorne wrote: "His patients are interesting to him only as subjects for some new experiment. He would sacrifice human life, his own among the rest, or whatever else was dearest to him, for the sake of adding so much as a grain of mustard seed to the great heap of his accumulated knowledge."

Godplayer (1983) is another combination of suspense, murder and medicine. Cook is concerned that unpoliced doctors are making ethical decisions only God is qualified to make. The book has two primary social concerns. The first is the failure of "peer review" to weed out incompetence. In Godplayer, physicians investigate their colleagues' blunders with all the vigilance of a Nixon Administration investigation of the Nixon Administration. Cook also is concerned about "the impaired physician"; a doctor's access to psychoactive drugs combines maximum temptation with maximum opportunity, resulting in addicted physicians who practice their profession as badly as addicted athletes

The protagonist is Dr. Cassandra Kingsley, perhaps Cook's most successful attempt at developing a rounded character. The omniscient narrator takes readers inside the head of a person with clear albeit conflicting motives, feelings and perceptions. Through Cassie, Cook does a very creditable job of creating suspense using a classic literary technique: the mental confusion and moral dilemmas that develop out of a person's realization she cannot distinguish between what is real and what is imagined — and how to act accordingly.

Cassie Kingsley is married to the country's foremost heart...