A Family Affair (novel)

A Family Affair is the last Nero Wolfe detective novel by Rex Stout, published by the Viking Press in 1975. The prolific author, who had penned more than 70 stories in the internationally successful Nero Wolfe series since 1934, died at the age of 88, less than six months after publication of this last book.
Plot summary.
A waiter at Rusterman's Restaurant turns up at Wolfe's front door late one night, claiming that a man is going to kill him. Shortly after Archie puts him in one of the spare bedrooms, the waiter dies when a bomb planted in his coat pocket explodes. Wolfe, outraged at the thought of such a violent act taking place in his own house, resolves to find the murderer without sharing any information with Inspector Cramer. Soon Wolfe and Archie find themselves investigating two additional murders: the earlier killing of a customer at Rusterman's, and the subsequent death of the waiter's daughter.
For much of the story, Stout leads the reader to believe that the central murder mystery is related to the Watergate scandal. Ultimately, Wolfe discovers that the killer is one of his closest associates, a character who had been appearing in Nero Wolfe mysteries for over forty years.
"A Family Affair" is an unusual Nero Wolfe mystery in that Archie reveals his (correct) opinion of the killer's identity well before Wolfe does so in the closing chapters.
Reviews and commentary.
"Time" reviewer J.F. Powers gave the book a favorable review, indicating that "even veteran aficionados will be hypnotized by this witty, complex mystery."