Foolish, convoluted, but mostly agreeable conspiracy-suspense--heavy on I-don't-believe-it! hysteria, though without the kidnap grabber of Sharp's Sunflower or the paranoia-power of vintage Robert Ludlum. Right from the start, the future-history here is implausible, especially with Reagan/Haig foreign policy in the air: dÃ‰tente is at its peak, and the US Prez and the USSR Premier are about to have a Human Rights summit on the Yugoslav isle of Korcula. But Peter Lucas, Asst. Sec. of State for Human Rights, is besieged by hints that something fishy's afoot: the Yugoslav ambassador is killed (poison cigarette) at the Kennedy Center Opera House; Peter's chum Steve (of Freedom International) is bomb-murdered, and his dying words are ""Investigate Marco Polo. . . remember the Soviet Six."" And indeed Peter, after being shot at, soon learns that three of those six dissidents have died while trying to escape to the West--with taped evidence of a plot to assassinate both Prez and Premier on Korcula. (Legend has it that Marco Polo was born on the island.) Can Peter prove--by stealing another future-technology tape from suddenly suspect Sec. of State Compton (his mentor and future father-in-law)--the existence of this assassination plot? What about the Soviet mole-spy at the White House? And is the whole shebang maybe a coverup for something even worse that's going to happen at Korcula--by the anti-dÃ‰tente Soviet leader who's been using Peter as a dupe, arranging for him to foil the secret, way-beyond-dÃ‰tente scheme (hilariously unconvincing) that's really the reason for the Summit on Korcula. Nonsensical at every turn, talky and confusing toward the end; but it's never distasteful, generally likable--and the twists and teases here should provide an okay stopgap for Ludlum fans who are impatiently waiting for that next big conspiracy-fest.