TWO YEARS AGO, Vladimir Bukovsky was abruptly yanked by the KGB from the depths of Vladimir Prison and flown off to the West in exchange for Chilean Communist leader Luis Covalan, who at that time was the Kremlin's number one pin-up among comrades jailed in capitalist countries. The Soviets were baffled to discover that, in the eyes of the world, by trading Bukovsky for Corvalan they had annointed this 33-year-old dissident who had spent most of his adult life behind bars as a political figure on a par with one of their Marxist heroes.

The Kremlin pilloried Bukovsky calling him "scum" and a "plaything of malicious and bellicose reactionary forces in the West." But President Jimmy Carter, then in the fullness of his human rights fervor, received Bukovsky at the White House. Next, Western publishers rushed to the fore and the young dissident racked up a hefty advance for his story, a sum said to be around $250,000.

Yet for all the distracting hoopla attendant to his departure, Bukovsky had proven himself over the years to be a real force in the small band of Soviet citizens willing to challenge the Kremlin authorities head-on. Beginning in the mid-'60s he organized rallies, collected information for correspondents and sent abroad the most complete dossiers on the conditions in mental asylums. Specialists here eagerly awaited Bukovsky's memoir of his years as a renegade in Soviet society as potentially the most interesting dissident book to come out of the U.S.S.R. since Solzhenitsyn's Gulag .

And indeed, this turns out to be a very fine work -- but for surprising reasons.

There is little that is unexpected in Bukovsky's account of prison life in Russia or even in his report of the appalling conditions in mental wards where KGB victims are sent. In most respects, Bukovsky's version squares with the testimony of other recent dissident emigres.

What makes his book special is that Bukovsky writes so well, with wry humor and a sense of irony that is almost picaresque at times. I was prepared for a rather dry recitation of repression, earnest in the utmost, but instead was entertained -- if that is what it can be called -- by tales of inmate resistance, portraits of bumptious cops and pithy insights into Soviet reality.

This is, therefore, very much the devastating book Vladimir Bukovsky was predicted to write, not for what he reveals but rather because he so skillfully makes buffoons of his villains -- which is doubtless as irksome to the men in the Kremlin as plain old rhetorical condemnation would be. Top Soviets are used to being railed at by the likes of Bukovsky.Being scoffed at, however, can probably still raise hackles in the offices around Red Square.

This random fragment captures something of Bukosvky's spirit:

"When I was at the Serbsky Institute for observation" (an especially dreaded establishment) "women working there as orderlies -- simple village bodies, almost all of them believers, with crucifixes hidden under their dresses -- used to feel sorry for us, especially for any of us who had come from jail or the labor camps all skinny and emaciated. They used to bring us things to eat on the sly.... And yet these same village women used to rat on us without mercy.... "If you asked them, 'Why do you do it? You're supposed to be Christians!' they replied: "We can't help it, its our job.' And it was useless to argue with them. Maybe Brezhnev's not such a bad fellow either, its just that he's got a lousy job."

From the time he was a teenager, Bukovsky was apparently inbued with extraordinary toughness, a deep hostility to Soviet regimentation and the courage to take on those responsible for its imposition. Combined with that strength and somehow leavening it was a distance Bukovsky maintained between himself and his tormentors that made it possible for him to see them as fundamentally ludicrous.

"My old friend General Svetlichny, head of the Moscow... KGB," Bukovsky describes as an "evil dwarf with the oversized head" "tramping wrathfully over... the parquet floor" of the "sumptuous mansion" of a prerevolutionary count. It is worth remembering that this fellow had consigned Bukovsky to a special form of torture, incarceration with madmen. Bukovsky, it seems, conquered his plight by making mock of it.

From the hundreds of anecdotes and small sketches, perhaps the most telling, at least for Americans, is the way Bukovsky and other prisoners took advantage of the Soviet penchant for bureaucracy. The passage reads like something out of Gogol:

"Under Soviet law, every prisoner has the right to petition any state or public institution and any public official with a complaint. Every complaint has to be forwarded by the prison administration within three days of its receipt. In the interim, the administration has to write an explanation to accompany the complaint, add relevant details from the prisoner's dossier, and put everything into the same envelope for further dispatch. The pbulic official or institution that receives the complaint records it in a daily register of incoming documents and must answer in a month. If the official or institution is not competent to deal with the matter complained of, he has to pass it on to someone who is. Repeated complaints set the whole machinery in motion each time they are made....

"You should write enormous numbers of complaints and send them to the officials least equipped to deal with them. At the height of our war, each of us wrote from ten to thirty complaints a day." Now that is subversive.

Read Vladimir Bukovsky. He portrays the darkest side of Soviet life. It is a limited picture, to be sure, and one that Americans should certainly not mistake for everything they need to know about the U.S.S.R. But it is a portrait wrought with a fine hand. That makes it especially valuable.