Those who follow the 87th Precinct series know that Fat Ollie Weeks is a bigoted, misogynistic, sloppy and (considerably) overweight detective from the neighboring 88th Precinct. He has an inflated sense of his own importance, and is a living, breathing, mass of contradictions, blind to his own considerable faults. This is best illustrated when we occasionally see Ollie waddling down the street and noticing a person who is overweight. Ollie, who often eats two large pizzas at a single sitting, prefers to think of himself as a "large" man and, for the life of him, he can't understand why these fat slobs don't have enough pride in themselves and enough self-discipline to lose some weight.
Ollie's only saving grace is that he's a pretty good detective. Although no one at the 87th precinct likes him, Ollie has horned in on a few of the detectives' cases there, usually when jurisdictions overlap, and he has often been of considerable assistance in solving difficult cases.
In this instance, a city councilman who is planning to run for the Mayor's office is assassinated while preparing for a campaign rally. Ollie joins Steve Carella and the other detectives of the 87th in an effort to solve the case.
At the same time, Ollie, who imagines himself as a brilliant author has written a novel. The novel is only thirty-seven pages long, but Ollie has labored hard over its creation and he assumes that the quality of the book will more than make up for its brevity. Ollie is en route to a copy shop and makes a quick stop, leaving his only copy of the manuscript in a briefcase in his car. He returns to the car to discover that some perp has done a smash and grab and has stolen the briefcase along with Oliie's precious manuscript.
Ollie is determined to catch the thief and recover his book, and his search, along with the hunt for the councilman's killer constitutes the plot of Fat Ollie's Book. Interspersed within the pages of McBain's novel are the pages of Ollie's novel which is flat out hilariously bad. It all makes for another entertaining read from the master of the police procedural.