T. S. Eliot claimed that “The Moonstone is the first, longest, and best of English detective novels,” and his praise has been repeated so often as almost to have become a commonplace. This praise, however, if not precisely faint, may yet be perceived as limited, since detective novels are widely regarded as light reading.

Moreover, praise of The Moonstone as a detective novel pays tribute to what in Wilkie Collins is both a strength and a weakness. It is commonly believed that detective fiction stands or falls on the coherence and ingenuity of its plot. From the beginning, critics recognized Collins’s gifts as a constructor of plots, but they often saw in his narratives a mechanical, manipulative quality they thought limited, if indeed it did not destroy, the human interest of his work.

Critical interest in Collins grew, however, as literature began to be less stringently divided into such categories as serious and popular, which would in any case have had little meaning for Collins or his great friend Charles Dickens. A renewed appreciation of Collins’s plot constructions was accompanied by growing recognition of how much there is in The Moonstone besides plot and by the acknowledgment of Collins’s achievement in integrating various elements to produce a whole that is both unified and vital.

To begin with, it is no small accomplishment to sustain the readers’ interest in the whereabouts of a missing diamond for the entire not inconsiderable length of the novel. That the mystery of the diamond is made to bear on a romantic plot involving Rachel Verinder and Franklin Blake increases the level of narrative complexity. That Collins brings both of these narrative lines of development to resolution in the same moment of discovery is an admirable feat of craft. In fact, Collins’s technical mastery, although dazzling in itself, accounts for only part of the satisfaction the novel offers its readers. The focus on the diamond means that readers are eager to reach the denouement and learn what has become of the stone, but it is the author’s triumph that the readers’ eagerness does not become impatience.

The plot emerges from a series of narratives conveyed by a heterogeneous set of narrators. The first, Gabriel Betteredge, is astonished to discover just how difficult it is to stick to the subject; he constantly needs to bring himself back to the point. Yet his digressions are among the greatest delights of the book. In addition to sustaining and intensifying suspense by delaying answers to narrative questions, the digressions reveal the man. In short, while contributing to the effectiveness of the plot, Betteredge’s digressions satisfy the readers’ interest in character, that other great concern of the novel as a literary form, especially in the nineteenth century. Collins in The Moonstone is a master at diverting the readers while making them wait for the denouement.

Betteredge is one of a number of strongly realized characters in The Moonstone. Each of the other narrators, perhaps most emphatically the evangelically inclined Miss Clack, expresses an interesting personality while telling part of the tale. Collins is, however, careful to reduce the quantity of digression as he approaches the resolution. Characters other than the narrators achieve a comparable vividness. Rosanna Spearman, the plain servant who dares to love a gentleman, and Ezra Jennings, the half-caste physician’s assistant who is instrumental in solving the mystery, are fascinating characters in their own right. They also provide Collins with an opportunity to engage and extend the sympathies of readers not accustomed to acknowledge the full humanity of Rosannas and Ezras.

While Collins’s portrayal of the Brahmins...