Dennis Nedry is the head computer programmer for Jurassic Park. He's also a slovenly, greedy excuse for a human being who doesn't think John Hammond is paying him enough dough. It is this desire for more money that leads him to listen very intently when Biosyn, a rival company of InGen's, pours a honeyed potion into his ear.
Nedry is first seen meeting with Dodgson, a representative from Biosyn, in an outdoor restaurant in San José.
Dodgson hires him to steal embryos of the fifteen dinosaur species InGen has developed for Jurassic Park, in exchange for an obscene amount of money. To transport them, Nedry is provided with a fake can of Barbasol shaving cream. Dodgson tells them there's enough coolant inside to keep the embryos viable for thirty-six hours, but Nedry isn't worred.
Once on the island, he begins putting his plan into motion. Due to how buggy Jurassic Park's computer system is, turning off the main power deactivates all the security locks, allowing Nedry to enter Jurassic Park's genetics laboratory and abscond with the embryos.
He passes the power outage off as a bug in the system, assuring everyone that some systems will "go on and off" randomly. Then he excuses himself, enters the lab, and swipes the embryos.
Now all he has to do is take a Jeep and drive to the island's docks. There, he'll deliver the Barbasol can to a Biosyn agent pretending to be a sailor on board a cargo ship, and return to the control room and restore power.
Nedry didn't count on a hurricane hitting the island, however.
The storm results in the ship needing to leave sooner than planned. So Nedry is forced to rush to try and reach the docks before the ship sets sail, with the end result that he gets lost in the downpour. Becoming increasingly edgy, he drives erratically, and winds up smashing through a fence and careening down a hill, where his Jeep gets wedged.
Getting out and leaving the driver's side door open, he unspools the vehicle's tow cable and wraps it around a tree, intended to use it to pull the Jeep free. In the process, he slips and falls, losing his glasses.
As he is securing the cable to the tree, he suddenly encounters a smallish, vaguely comical dinosaur called a Dilophosaurus, which hoots and chirps cutely at him.
Unconcerned, he attempts to make the animal leave by throwing a stick for it to fetch.
When it doesn't, Nedry becomes annoyed. "Eh, no wonder you're extinct!" he sneers, vowing, "I'm gonna run you over when I come back down!"
He walks back to his Jeep, where the door is still hanging open, but falls again, and, turning, notices that the Dilophosaurus has followed him. Suddenly, it begins hissing like a rattlesnake, unfurling an enormous frill around his neck.
It spits a thick, goopy tar-like substances onto his shirt. Earlier in the film, it'd been stated that Dilophosaurs were poisonous, and Nedry is finding this out firsthand. Getting up, he makes it to his Jeep, but makes the mistake of turning back to look at the dinosaur one final time, and takes a second volley of its poisonous phlegm right in the eyes. He screams in agony as he's painfully blinded.
Attempting to get into the Jeep, he hits his head on the door frame and falls. The Barbasol can falls out of his coat and rolls down the hill, where it becomes buried in the mud. Managing to pick himself up, Nedry clambers into the perceived safety of the Jeep and shuts the door... only to discover that a second Dilophosaurus, which crawled in earlier because he left the door open the entire time, is now sitting in the passenger seat. It snarls angrily at him.
We cut to an exterior view of the vehicle, which begins rocking back and forth erratically as Nedry screams...