Some years ago, reviewing a novel by Robert Coover, Wilfrid Sheed said that "not to read it because you don't like baseball is like not reading Balzac because you don't like boarding houses." I bring this up because I am entirely innocent of race tracks. And yet: Not to read Dick Francis because you don't like horses is like not reading Dostoyevsky because you don't like God. Baseball, boarding houses, race tracks and God are subcultures. A writer has to have a subculture to stand up on….

What distinguishes "Reflex" from other Dick Francis fictions is its multitude of plots, all of them connecting, as if the artist were a spider with galactic aspirations for the latest web. What distinguishes Philip from previous reluctant heroes in Dick Francis fictions is that he is as much a photographer as he is a jockey, and we learn as much about developing film as we do about the steeplechase.

A camera, Philip tells us, is "your shield. Keeps you a step away from the world. Makes you an observer. Gives you an excuse not to feel." Perhaps. Certainly, in the movies of Antonioni and the novels of Jerzy Kosinski, the darkroom is as important as boarding houses were to Balzac and the bull was to Hemingway.

"Reflex" enthralls. Not the least of Mr. Francis's many accomplishments in his most complicated and successful mystery is that he introduces two characters who are supposed to be intelligent and who actually prove themselves to be so—a splendid performance.