Bushmaster Fall

The frightening purpose of a U.S.-funded experiment in the Bolivian rain forest unfolds to powerful effect in Posey's ( Prospero Drill ) outstanding thriller. Ostensibly intended to measure the absorption of radiation, the Amecos project has been over for several years, and all that remains are shacks and a British naturalist, Joly Goodpasture, who is studying the flora and fauna. Goodpasture is horrified to discover that a recent meteor shower has left no physical evidence of a meteorite but has instead saturated the area with a radioactive substance. His mission to map the ``hot spots'' involves, variously, a KGB agent posing as a Canadian astronomer, a State Department operative, a drug lord, a Shining Path guerrilla, a member of Greenpeace. Each of these characters operates according to complicated, idiosyncratic but credible motives, all of which Posey orchestrates into a surreal, and very satisfying, resolution. (Feb.)