They stand in counterbalance to a well-known mathematician and chaos theorist Ian Malcolm and a lawyer representing the investors, Donald Gennaro. Recent events have worried Hammond's considerable investors, so, to placate them, he means for Grant and Sattler to act as fresh consultants. Paleontologist Alan Grant and his paleobotanist graduate student Ellie Sattler are abruptly whisked away by millionaire John Hammond (founder and CEO of 'International Genetic Technologies', or InGen) for a weekend visit to a 'biological preserve' he has established on an island 120 miles west off the coast of Costa Rica.

The narrative begins by slowly tying together a series of incidents involving strange animal attacks in Costa Rica and on Isla Nublar, the main setting for the story, in one horrific incident, three Compsognathus killed a baby at a hospital in Bahía Anasco.