In issue #1, After a park worker is killed by a Velociraptor, the park's investors, represented by lawyer Donald Gennaro, demand that experts visit the park and certify it as safe. Gennaro invites the mathematician Ian Malcolm while Hammond invites paleontologist Dr. Alan Grant and paleobotanist Dr. Ellie Sattler. Upon arrival, the group is stunned to see three Brachiosaurus and a herd of Parasaurolophus in the distance. 

Next in issue #2, At the visitor center, the group learns during a laboratory tour that the cloning was accomplished by extracting the DNA of dinosaurs from mosquitoes that had been preserved in amber. The DNA strands were incomplete, so DNA from frogs was used to fill in the gaps. The dinosaurs were all cloned genetically as females in order to prevent breeding. The group is then joined by Hammond's grandchildren, Lex and Tim Murphy for a tour of the park, while Hammond oversees the trip from the park's control room. The tour does not go as planned. 

Next in issue #3, With the dinosaurs failing to appear and a Triceratops becoming ill. As a tropical storm approaches Isla Nublar, the tour is cut short. Most of the park employees depart on a boat for the mainland and the visitors return to the electric tour vehicles, except Ellie, who stays with the park's veterinarian to study the Triceratops. During the storm, as night falls, Jurassic Park's computer programmer, Dennis Nedry, who has been bribed by a corporate rival to steal dinosaur embryos, deactivates the park's security system to allow him access to the embryo storage room. The power goes out, and the tour vehicles become stuck. Most of the park's electric fences are deactivated, allowing the Tyrannosaurus rex to escape and attack the tour group. Grant, Lex, Tim, Gennaro, and Malcolm find themselves face to face with one hungry T. Rex. The T. Rex. soon devours Gennaro, injures Malcolm, and the turns to Grant and Lex. 

Finally, in issue #4, The Tyrannosaurus Rex terror continues as it pushes one of the vehicles over an embankment, but Grant, Lex, and Tim narrowly escape. Meanwhile, on his way to deliver the embryos to the island's docks, Nedry becomes lost in the dark, crashes his Jeep, and is killed by a Dilophosaurus. Sattler assists the park's game warden, Robert Muldoon, in a search for survivors, but they only find Malcolm before the Tyrannosaurus rex returns. They escape in one of the vehicles. Unable to decipher Nedry's code to reactivate the security system, Hammond and the park's chief engineer Ray Arnold opt to reboot the entire park's system. The group shuts down the park's grid and retreats to an emergency bunker, while Arnold heads to a maintenance shed to complete the rebooting process. When he fails to return, Sattler and Muldoon head to the shed as well. They discover the shutdown has deactivated the remaining fences and released the Velociraptors; Muldoon distracts the raptors while Sattler turns the power back on. She discovers Arnold's severed arm and escapes. Soon after, the raptors ambush and kill Muldoon. Grant, Tim, and Lex discover the broken shells of dinosaur eggs. Grant concludes that the dinosaurs have been breeding, which occurred because they have the genetic coding of frog DNA - West African bullfrogs can change their sex in a single-sex environment, making the dinosaurs able to do so as well. On the way back to the visitor center, the trio encounter a herd of Gallimimus, when suddenly the Tyrannosaurus emerges from seemingly nowhere and kills one. Grant, Tim and Lex reach the visitor center, and Grant leaves them there as he goes searching for the others. After finding the bunker, Grant and Sattler head back to the visitor center, where the children successfully evade two Velociraptors. The four head to the control room, where Lex restores full power, allowing the group to call for help. While trying to leave, they are cornered by the raptors, but escape when the Tyrannosaurus suddenly appears and kills both raptors, ignoring the humans. Hammond arrives in a jeep with Malcolm, and the entire group flees together. Before they board a helicopter to leave the island, Grant decides not to endorse the park, a choice with which Hammond concurs.