As Jaws meets Jurassic Park, Meg (short for megladon) brings us a 60-foot, 20-ton prehistoric shark with a nine-foot-wide mouth that is likely to gobble up bestseller lists, as well as reappear in 1998 as a summer blockbuster. In rather characterless prose, debut novelist Alten's well-groomed story rockets like a pre-edited filmscript from event to event. But the author's love of his title character is clear, as he keeps his Lord and Master of the Sea, a female Carcharodon Megalodon, frequently front and center. Seven years ago, Professor Jonas Taylor, a paleontologist and deep-sea submersible pilot, first saw such a shark, thought to be extinct, while diving more than seven miles down in the Marianas Trench. During the Ice Age, members of the species, it turns out, took refuge in the hot thermals on the ocean bottom. Lethally cold water above has kept from them resurfacing. Jonas's first encounter cost two lives, and has burdened him with profound guilt. He goes back down to the abyss anyway, accompanied by Masao Tanaka, the owner of a huge aquarium on the California coast. When a male Megalodon gets entrapped in steel cables in the trench, he's attacked by a pregnant female; she follows the male to the surface, surviving the journey, and discovers a warm new world, filled with varied, easy, hot-blooded prey. Clearly, the shark is an ecological disaster, especially when she gives birth to three more of her kind. Taylor and Tanaka, however, don't want to destroy the shark but rather to harness her drugged body and haul it into confinement. This means some vastly dangerous close work with her once she's located, with Taylor hovering about the monster in a submersible that becomes the instrument of an utterly amazing climax. A female offspring in captivity at story's end guarantees a sequel. Weightless characters on a choppy sea--but hellishly riveting.