The narrative spine of the novel bridges a long weekend in the life of Aaron Benham, a clinically depressed literature professor at a New Hampshire college who has taken a leave of absence to write a novel, also called "The Hair of Harold Roux."

Aaron is interrupted by a succession of phone calls—first, from the mother of one of his students, who seems to have vanished; second, from the wife of a colleague at the college, George, who is neglecting his dissertation and is in danger of losing his job.

Stewing in his remorse, Aaron recalls an incident involving his missing student, Mark Rasmussen, who had persuaded him to work for a day on a fishing excursion boat as a way to experience life outside academia.

On the boat, Aaron is enraged when the drunken guests begin to snag flying gulls with baited fish hooks; he halts the depravity by punching one of the perpetrators, a descent into violence that leaves him ashamed and depressed.

The novel within the novel centers on Allard Benson, an Army veteran turned college student, and his friend Harold Roux, a failed seminarian and deputy infantry chaplain who has gone prematurely bald and adopted an unfortunate toupée.

Allard and Harold also do battle with one Boom Maloumian, an obese Armenian student who terrorizes their dormitory and regales them with vulgar tales of military life.

A visit to meet Mary's devoutly Catholic father, coupled with trip to Sunday mass, leaves Allard conflicted over his sexual longing for a woman whose religious faith he finds ludicrous and destructive.

Still in pain, Aaron manages to attend a hastily called meeting of senior department faculty at which George's failure to complete his dissertation is to be addressed.

The party descends into total chaos when Boom Maloumian, drunk and angry that he had not been invited, arrives with several belligerent fraternity brothers and a prostitute.

The scene ends in violence, sexual assault, a spectacular (and literal) train wreck, and the departure of Harold, presumably forever and without his novel manuscript or his hairpiece.

One year, the family fails to receive their annual October visit from a trader upon whom they depend for winter provisions in exchange for their handmade knives and moccasins.