In Boomerang Hannah most often focuses on a turning point, outrageous exploit, or bizarre escapade from his past. Scarcely prefaced with any exposition, most of these events are linked only by Hannah's memory. Hannah focuses on ends and actions rather than means or motives. His prose is lean, sparse, colloquial, and sometimes exasperatingly terse. Many of the episodes revolve around music, fishing, animals, or firearms. Most of them stand as parables of the confrontation of meanness and generosity, tolerance and intolerance, humanity and inhumanity.

One of Hannah's principal satirical targets is organized religion. His hatred of southern fundamentalism, Catholicism, and Moslem zealotry grows out of his conviction that organized religion thwarts and diminishes the individual. Although Hannah mentions that he "prays," his God is a pantheistic or at least non-sectarian deity; he dreads and fears the "Christers" for their hypocrisy, priggishness, and sanctimony.

More than even his previous novels, Boomerang focuses on men of action. Women appear almost exclusively as real or potential sexual partners. Not surprisingly, feminism is one of the modern phenomena Hannah distrusts most.

Hannah deals extensively with families in this novel. He speaks often of his three marriages, his own children, his wife's son, other families. With surprising frequency, these families suffer because of the random and violent death of a family member. A young father dies of a heart attack on a golf course; a four-year old is killed by a shotgun blast while sitting in the family car; a beloved son and husband is murdered by "drug pirates." The randomness of these deaths deeply troubles Hannah, but only intensifies his reverence for life itself. Other families are often divided by divorce or by rancorous discord. Yet the family provides some measure of stability in a world filled with capricious disasters. In Boomerang Hannah's memories become parables intended to pass on whatever wisdom or virtue is embodied in the deeds of his characters. The title itself suggests the truisms: what goes around, comes around; or as you sow, so shall you reap.

Hannah's political and social views often appear self-contradictory; he emerges as a liberal reactionary: an animal rights activist who is also given to the occasional racial epithet; a man who despises Republicans but who teems with patriotic pride; a womanizer who dwells on the importance of families. But although he makes no apologies for his often outrageous opinions, he admits his own fallibility by remarking: "I am full of error myself," "I am a terrible man," or "I move through life without a conscience."