NEWS HAS REACHED ROME that a pillar of the Church, the Portuguese missionary Christovao Fereira, has apostatized in Japan, and three of his former students, shocked and stunned by the report, set out in March of 1638 to determine whether it is true. This is no longer "the Japan that Frances Xavier, in the middle of the 16th century, found so hospitable to the spread of Christianity; in a reversal of policy in 1587, Hideyoshi began a dreadful persecution of native and foreign Christians alike, and in 1614 Tokigawa Ieyasu ordered the expulsion of all missionaries from Japan. Ferreira was a member of the small underground contingent that had remained.

This is the climate in which Sabastian Rodrigues and Francisco Garrpe arrive in Japan. (The third member of their party is prevented by malaria from completing the journey.) The pair sails on a Chinese ship from Macao, in the company of a drunken, fawning, devious Japanese named Kichijiro, possibly a Christian, on whom they are forced to rely. Kichijiro does facilitate their illegal midnight entry into the country and into the temporary sanctuary of a small Christian community near the coast. For a time, Rodrigues and Garrpe perform their priestly functions from the hut in which they live concealed, and they remain in hiding, or in flight, until they are betrayed, and separately taken.

This is the background and beginning of this powerful novel. Events are seen in the main through the eyes of Rodrigues, at first by means of the letters he sends back to Portugal, and then through the journal he is permitted to keep in captivity. From time to time the narrative, still focussed on Rodrigues, slips unobtrusively into the third person, and subtly and economically conveys the flavor of the country and the time.

While still in Goa, Rodrigues has been warned about the magistrate Inoue, a former Christian himself and "cunning as a serpent," at whose hands Ferreira is said to have apostatized. In due course Rodrigues falls into Ioue's hands, and his faith is tried to the limit. From spiritual pride, perhaps, Rodrigues has often compared his grim situation to that of 'Christ's agony at Gethsemane; he sees the obsequious Kichijiro, who winds in and out of the story in unpredictable fashion, alternately assisting Rodrigues, betraying him and asking absolution, as the Judas-figure in his own drama. He is sickened by the atrocious tortures undergone by some of the Japanese Christians to whom he has ministered. Not himself physically molested, Rodrigues gradually weakens before the shrewd strategy of Inoue and the character called "the interpreter," who relentlessly impress upon him the fact that his own stubbornness is the cause of the suffering inflicted on the "simpleminded Japanese. (The primitive Christianity of the peasants, he is assured, results from a confusion of the word "Deus" with the word "Dainichi, the Shinto god of the sun.) If he were only to apostatize, perform the "mere formality" of treading on the fumie -- stepping, that is, on the likeness of his beloved Christ, whose face in its many manifestations has obsessed him since his childhood, and whose silence in the fact of the unspeakable gives the book its name -- then further tragedy would be avoided.

Believing at one point that he is finally going to meet Ferreira, he is confronted instead with Garrpe, but from a distance, and watches as his former comrade swims to his death in fruitless pursuit of a boat which is carrying Japanese Christians to a watery grave. And so, while suicide is a sin, Garrpe's desperate act, which will haunt Rodrigues thereafter, proves that an honorable death this side of apostasy is possible. And yet, Rodrigues tells himself, "a priest does not exist in order to become a martyr; he must preserve his life in order that the flame of faith may not utterly die when the church is persecuted." And yet, in the aftermath of a beheading, "What he could not understand was the stillness of the courtyard, the voice of the cicada, the whirling wings of the flies.A man had died. Yet the outside world went on as if nothing had happened . . . Was this martyrdom? Why are you silent?"

Finally he is brought to meet Ferreira at a Buddhist temple. His former mentor is wearing a black kimono, and his hair is bound back in Japanese style. He is also beardless, which for some reason shocks Rodrigues most. He has been translating, Ferreira says, a book on astronomy -- "'I am of some use to the people of this country'" -- at which point the interpreter gleefully interjects that he is also at work on a book refuting the teachings of Christianity. It was not when he was himself suspended upside down in the pit for several days that he apostatized, Ferreira says; it was afterward, when by doing so he could cut short the suffering of others.

This is the first of two shuddering confrontations Rodrigues has with Ferreira. Between times, back in his miserable cell, he is mightily annoyed by what he takes to be the snoring of the guard outside his door. He beats finally on the wall, and the interpreter appears, along with Ferreira. What he hears is not snoring, they tell him, but the moaning of Christians hanging in the pit. And Ferreira bores mordantly on. He occupied that same cell himself, he tells Rodrigues. "'Now you are going to perform the most painful act of love that has ever been performed,'" he says at last.Rodrigues is led out, and in unfathomable spiritual agony, he "placed his foot on the fumie . Dawn broke. And far in the distance the cock crew."

The final chapter of this profoundly moving, profoundly disturbing book consists of excerpts from the diary of a Dutch clerk in Nagasaki in which the drama that we have been so intimately exposed to is seen from the remote perspective of a man concerned with commercial matters. The feeling is similar to viewing the action off in a corner of a Brueghel painting, or to watching a figure almost lost in the mists of a Japanese scroll. This chapter is followed by an appendix called "Diary of an Officer at the Christian Residence," a detailed, humdrum account of life on the estate in Tokyo to which Rodrigues, having taken on the identity and family (as had also Ferreira) of a deceased Japanese, is sent to live, and 30 years later, uneventfully dies.

Shusaku Endo was born in 1923 and is described on the dust jacket as "the leading writer in Japan." On the strength of this splendid novel, he may very well be. The quotation from Graham Greene on the front cover -- "In my opinion one of the finest novels of our time" -- does not seem like hyperbole. It is astonishing to consider that Silence is the first full-length work by this novelist to appear in this country, and to learn that the translation by William Johnston, a brilliant, subtle piece of work with not a line akilter, was published in 1969 by Sophia University Press in Tokyo, but apparently gained no currency. Rather than ponder the mysteries surrounding the book's tardy arrival, however, it is probably better to be thankful for it, and for the news that other works of Endo are to follow.