Milo Hoffman (Ryan Phillippe) has just been hired away from an upstart software company to join NURV, a computer giant modeled after Microsoft. NURV's CEO Gary Winston (Tim Robbins, physically resembling Bill Gates) hired Milo to work on Synapse, a media distribution network that can be accessed from anywhere (television, computer, hand-held device, etc.) but is in danger of missing it's launch date. Milo and his girlfriend Alice (Claire Forlani) move to NURV's campus in Portland, Oregon.
When Milo needs source code to complete his job, Gary gives it to him almost immediately, claiming he had just come up with it. Later, Milo's best friend Terry is murdered, and the code he was working on suddenly appears, and Gary claims he came up with it. After some investigating, Milo discovers that most of the code for Synapse came from non-NURV programmers, who were murdered after their code was stolen. NURV knew of the other programmers through an extensive surveillance system, and NURV is also using that system on their own employees as well. Milo also learns that NURV has infiltrated the Justice Department and many media outlets, so going to them with what he knows will be fruitless. He also learns that Alice is actually an ex-con who was hired by NURV to pretend to be his girlfriend and to convince Milo to join their company when they called. Despite the betrayal, Milo convinces Alice to join with him and help bring down NURV.
With the help of another NURV programmer named Lisa (Rachael Leigh Cook), Milo comes up with a plan to hijack Synapse and broadcast NURV's and Gary Winston's crimes around the world from a local public-access television station. Milo's plan fails, however, when Lisa prevents the Synapse signal from being uploaded to NURV's satellites, revealing herself to be a double-agent. With Milo being taken back to NURV and facing certain death, Alice and one of Milo's old software company friends go to his back-up plan. Milo had made a second copy of the file that he was going to broadcast on Synapse and they uploaded that file from one of NURV's internal servers to the satellite.
Plan B succeeded, and the evidence that Milo collected showing NURV's and Gary Winston's crimes are broadcast all over the world, including the original source code that would make Synapse free to anyone. The FBI quickly arrives at Gary's house (where he was about to kill Milo) and everyone involved in the conspiracy is arrested, except Alice, who Milo allowed to get away. At the end, NURV is out of business, and Milo rejoins his old software company.