Upon returning home from an official party, a Czech government official and his wife discover it bugged and surveilled by mysterious figures, driving them to paranoia and intensifying their discontents with one another.

In the dead of night, a few hours after Mozart's death, the usual suspects are summoned to Mozart's room by Count Pergen, head of the secret police, who considered Mozart a potential revolutionary. Over the corpse, he interrogates them, trying to discover the true cause and significance of Mozart's demise.