Isla Sorna, codenamed “Site B” by the InGen company, is situated 87 miles southwest of Isla Nublar. During their vacation on a private yacht, a British couple faces tragedy when their daughter is taken by dinosaurs after she explores the beach alone.

Meanwhile, Ian Malcolm finds himself in a tense confrontation with Peter Ludlow, the new CEO of InGen, portrayed by Arliss Howard. Ludlow confronts Malcolm about allegations he supposedly made regarding Isla Nublar, accusing him of tarnishing the company’s reputation for financial gain. Malcolm learns that his university tenure has been unjustly cancelled due to this smear campaign, leaving his credibility in ruins.

Hammond, played by Richard Attenborough, explains to Malcolm that Site B was formerly a breeding ground for dinosaurs. After Hurricane Clarissa, these creatures gained complete freedom, living undisturbed in their natural environment for the past four years, developing their unique social structures. He refers to Site B as the “factory floor,” while Nublar is described as the “showroom.” Although initially engineered to have a lysine deficiency that would inevitably lead to their demise, the dinosaurs have oddly managed to thrive.

Hammond pleads with Malcolm to lead a team to document the dinosaurs, needing substantial photographic evidence to garner public support against the exploitation of Site B by Ludlow and InGen, who are eyeing it as a revenue-generating venture. Despite his hesitance, Malcolm discovers that Sarah Harding, his former girlfriend, has already journeyed to the island with plans to study the dinosaurs. With the urgency to rescue her, Malcolm assembles a team, including Eddie Carr and Nick Van Owen, alongside his daughter Kelly, who secretly manages to tag along.

As they venture deeper into Site B, they utilize technology to locate Sarah, who has stumbled upon some groundbreaking revelations about the dinosaurs’ behavior. She unveils that many herbivores have adapted their diets to survive, while carnivores prey on these herbivores for their necessary lysine intake. Malcolm finds himself in both awe and disbelief as Sarah challenges the existing narratives surrounding dinosaurs, claiming they behave much like nurturing parents, including the infamous T-Rex, which does not abandon its young.

Dark developments unfold when Ludlow enlists Roland Tembo, a seasoned big-game hunter, to capture important dinosaur specimens, including a T-Rex. However, Tembo discovers an infant T-Rex and resorts to cruel methods in hopes of luring its parents towards a deadly trap. Chaos erupts when Nick infiltrates the camp, sabotaging the captures and setting free other dinosaurs, leading to all-out pandemonium on the island.

Amidst the turmoil, Malcolm manages to provide emergency aid to the injured infant T-Rex, but quickly finds himself battling adult T-Rexes that threaten their lives. As their RV teeters on the edge of a cliff, Eddie heroically binds it to a tree but tragically pays the ultimate price as he faces the wrath of the dinosaurs.

As they retreat to the safety of their vehicle, they devise a plan to escape the island. However, raptors pose an imminent danger, leading to frantic encounters as they navigate their way through the chaos. Under the cover of night, as tensions mount, Malcolm succeeds in sending a distress signal to their awaiting rescue boat.

In a series of frantic events, helicopters touch down, and the captured T-Rex is transported to a ship bound for San Diego. Yet, disaster strikes as the adult T-Rex escapes and wreaks havoc in the city. Determined to rectify the situation, Malcolm and Sarah devise a plan to lure the rogue dinosaur back using the captured infant T-Rex, leading to a dramatic confrontation on the docks. When the adult T-Rex appears, chaos ensues, culminating in a desperate struggle for survival.

Amid the ensuing chaos, Sarah launches a tranquilizer dart that finally secures the adult T-Rex, and as calm returns, military forces prepare to escort the ship back to Isla Sorna, leaving behind a trail of destruction and a reminder of the raw, untamed power of nature.