Gray and Zach boarded a ferry boat to Masrani Global Corporation's famous dinosaur theme park; Jurassic World, whose aunt, Claire Dearing, was Senior Assets Manager for. They were supervised by Claire's personal assistant Zara Young, as Claire was too busy to spend time with her nephews. While there, they got to see many of Jurassic World's attractions, including the Mosasaurus Feeding Show, Underwater Observatory, and the Gyrosphere.
Gray and Zach were in their Gyrosphere when Jurassic World's only Indominus rex escaped her paddock. Eventually, the hybrid went into the Gyrosphere enclosure sometime after her escape and attacked them. The I. rex kicked Gray and his brother's vehicle between two Ankylosaurus, who were fleeing from the hybrid. Because they got too close to the ankylosaurs, one of the Ankylosaurus swung its clubbed tail at the spherical vehicle. Despite the multiple threats to the two brothers lives, they ultimately escaped the enclosure alive. Gray and his brother went into the wilderness of Isla Nublar, where they went inside what remained of the old Visitor Center built for the canceled Jurassic Park. The two brothers enter the Visitor Center's garage, where they manage to get an old Jurassic Park tour vehicle parked inside the garage, to work again, which they used to drive back to Jurassic World.
Eventually, he and his brother made it back to Jurassic World and were among the many civilians in Main Street when the inhabitants of the Isla Nublar Aviary went through the street attacking many of the people there. They witnessed a Pteranodon grab Zara and fly off with her, which resulted in Zara falling into the Mosasaurus containment tank and both her and the Pteranodon being consumed by the aforementioned reptile.
What followed after the pterosaurs was the Indominus rex who attacked Gray and his brother Zach, but Owen Grady who had spent the whole incident pursuing the hybrid protected the two boys from her attacks.
Gray is very intelligent, hyperactive, having a liking of science and maths, especially dinosaurs,similar to Tim Murphy. As was typical of kids his age, he was exceedingly hyper, impatient and easily excited by dinosaurs, which was a cause of annoyance for his older brother. He was also quite sensitive, as he burst into tears at the knowledge of his parents divorce and his brother's indifferent attitude. Though obviously frightened by his ordeal on the island, Gray was also quite brave as he stunned a raptor with a cattle prod with little assistance.