IN 1949, the Hungarian ambassador in Paris, a hero of the Spanish Civil War and the anti-Nazi resistance, received a message from his old comrade and teacher, now a high official in the Communist Part in Budapest. The party had lost touch with the masses, the message said, and an uprising was needed to restore the party's leading role.

The ambassador promptly reported to the authorities that his old comrade had sent that outrageous, seditious message.

Within a few weeks, the ambassador was recalled and charged with plotting with his old comrade to overthrow the government. Both men admitted guilt.

The truth is that neither man sent such a message.

Having joined the party as youthful idealists, they could not conceive of it making a mistake. They even agreed to revise their pasts: instead of anti-Nazi heroes they portrayed themselves as agents of the Gestapo. They accepted the party's argument that it now needed traitors, not heroes.

Istvan Orkeny's "Screenplay" at Arena Stage is a stunningly authentic re-creation of the century's great communist drama: communists killing communists. The victims accepted the absurd verdict of their persecutors as "the scientifically correct will of the party" and agreed that the party, the infallible vanguard of the proletariat, was to be kept eternally pure by such purges.

Under Stalin's rule, in each communist nation the best and the brightest in the movement cooperated in devising elaborate scripts--hence the title "Screenplay"--in which former underground communists denounced themselves as stool pigeons, murderers of true communists, opportunists, and agents of Washington and London and Belgrade, the Vatican and Tel Aviv.

In Orkeny's play, truth and falsehood, false confession and pure faith are mixed like hot gravy and cold sour cream. Different resistance movements--anti-Nazi and anti-Stalinist--simmer in a goulash of time splits and space warps, stirred continuously by the mysterious Maestro, the hypnotist. The anti-Nazi uprising the protagonist calls for in a proclamation in 1944 (true) fails to materialize. But in his 1949 trial that proclamation comes back to haunt him as a charge (false) of a call for an uprising against the Stalinist regime. And eventually, in 1956, the protagonist, a victim of Stalinist terror, is drafted as the leader of a genuinely popular rebellion.

Was that in some way the same uprising, 12 years too late? Could he have been indeed guilty, if in thought only, for plotting that uprising in 1949? As a true communist, shouldn't he have rejected the leadership role the masses thrust upon him in 1956, and have ordered the police to fire at the demonstrators?

He is shot for his role in that final revolution.

The protagonist, Adam Barabas, is a composite of at least three figures of recent Hungarian history. The first is anti-Nazi underground fighter Laszlo Rajk, the communist regime's ruthless minister in charge of internal security and, later, its foreign minister. In 1949, he was executed as the principal conspirator--as well as Gestapo agent and Yugoslav spy--in Hungary's most famous show trial. The second model is Imre Nagy, an anti-Stalinist, nationalist communist who became premier during the 1956 revolution and was shot after a secret trial in 1958. The third reference is to Janos Kadar--once a comrade and friend of both Rajk and Nagy--who presided over the execution of both. Kadar has been the party's first secretary since Soviet troops crushed the revolution of 1956.

But perhaps such footnotes of politics are exercises in pedagogy. "Screenplay" stands on its own as a titillating visual and verbal theater of the absurd. Above and beyond the incidents of time and space, "Screenplay" is a tale of personal loyalty and state deception, of wartime friendship and peacetime betrayal.

The first act unfolds the events--the chronology is juggled, the action is fast. The second act is a philosophical commentary, balancing the demands of censorship against the need for a moral last testament. (Orkeny was dying as he finished his play. According to Budapest gossip, on his deathbed he wrested a promise from the minister in charge of culture that "Screenplay" would be performed in Hungary. And it was.)

Orkeny's message is ambiguous and ambivalent, neither truly cynical nor even minimally idealistic. It is a political sleight-of-hand and a literary high-wire act--an acrobatics of howevers and nonethelesses that ends with the protagonist shot on a trapeze and disappearing through a trap door. He does not make any appearance after that, not even for a final bow.

But a basic, brutal message is conveyed by the Red Army soldiers who, with submachine guns in hand, leap onto the stage to restore order every time their comrades' passions really get out of hand.