Dr. Alan Grant, a renowned paleontologist, is struggling to secure funding for his research on dinosaur behavior. When he is approached by Paul and Amanda Kirby, a wealthy couple looking to fly over the infamous Isla Sorna, Grant sees an opportunity to fund his work and agrees to accompany them.
However, as they fly over the island, the Kirbys reveal their true intentions: they are looking for their son, who has been lost on the island after a parasailing accident. Despite Grant's protests, the group lands on the island and begins their search.
Before long, they encounter a pack of Velociraptors, who have only grown more cunning and dangerous since their escape from the original Jurassic Park. As they try to avoid the predators and find the Kirbys' son, the group realizes that they are not alone on the island. A new breed of dinosaur, the Spinosaurus, has been introduced to the ecosystem and is even more deadly than the Raptors.
As the group fights for survival, Grant must use his knowledge of dinosaur behavior to outsmart their attackers and protect the group. Along the way, he also begins to understand the true nature of these prehistoric creatures, and how humans have meddled with the natural order of things. In the end, they are rescued by the military, but not before experiencing the deadly consequences of playing God with nature.