Martin Dysart, a psychiatrist, is confronted with Alan Strang, a young man who has blinded six horses. To the owner of the horses the horror is simple: he was unlucky enough to employ a lunatic. To the boy's parents it is a hideous mystery; Alan has always adored horses and, although Dora Strang may be a slightly overindulgent mother and Frank Strang a slightly cantankerous father, they both love their son.
To Dysart, it is a psychological puzzle to be untangled to alleviate pain or, given his profession, that is what it ought to be. As it turns out, it is something far more complex and disturbing: a confrontation with himself as well as with Alan in which he comes to an inescapable view of man's need to worship and the distortions forced on that need by society.