A cotton-candy science thriller, Crichton's first novel in seven years matches neither the hardcore suspense nor the wit of his The Andromeda Strain, The Great Train Robbery, or Congo. But this spirited tale of a science team sent to explore a spaceship found on the Pacific floor does engross via its rich seeding of techno/oceanic lore and a happy plot that bounces merrily along from one surprise to the next. Reflecting his own march into middle-age, Crichton here offers his oldest hero yet, 53-year-old psychologist Norman Johnson, expert in the embryonic field of alien contact. Johnson is whisked off by the Navy to the South Seas along with five other scientists, most notably young black math-whiz Harold Adams and pretty zoologist Beth Halpern. After a shocking debriefing--they're told about the alien ship lying 1000 feet below the waves--the five descend by minisub to a deep-sea habitat. From there, the band explores the spaceship--which they deduce is an earth ship that traveled here from the future via a black hole--and find the sphere: a 30-foot wide hollow silver ball, clearly an alien artifact. All this is intriguing stuff, but without much tension; so Crichton dusts off an old ploy; he isolates his characters by whipping up a typhoon that cuts off surface aid, and then transforms the sphere into a Pandora's box of horrors. Adams finds his way into the sphere; after he emerges, it starts communicating via the habitat's computer, claiming to be hosted by an alien named "Jerry." Cute? Not when "Jerry" takes credit for the deadly jellyfish and giant squid that attack the habitat, killing all but Adams, Beth, and Norman. Norman and Beth soon figure out that "Jerry" is really Adams, who's been empowered by the sphere to make nightmares come true; but when they knock him out, the attacks continue, setting up Crichton's final conjuror's cache of tricks and twists, and a pleasingly upbeat ending. This sphere's as lightweight as a balloon floating up and away; but the ascent is swift, smooth, and loads of fun.