David Nix is an inventor and the mayor of Tomorrowland, but, unlike Frank and many other "dreamers", he values technological achievement over scientific creativity.
"Frank's idea was to create things that are fun, that make people's lives better because they bring pleasure and joy, and express hope. Nix is only interested in the more utilitarian platform of research; life for him is an endless scientific quest because he believes that man was put on this Earth to accumulate and develop knowledge."
Frank Walker first encounters David Nix at the 1964 World's Fair. When an 11 year old Frank enters "Tomorrowland," Nix is the one that kicks him out. Nix values technical accomplishment over creative thinking, and, when he throws Frank out of Tomorrowland, he banishes every other creative thinker. This allows Nix to focus purely on aesthetics and technical advancement for its own sake.
Years later, Nix has been the mayor of Tomorrowland for many years, and has become corrupt and deluded. After discovering that the world would end, he used the Monitor to broadcast the warning to humanity. When they did nothing to stop it, he continued broadcasting, causing the world's end to hasten and become a self-fulfilling prophecy.
After Frank returns with Athena and Casey Newton using the Spectacle, a secret entrance created by Plus Ultra, they meet up with Nix, who takes them to his Monitor and reveals that the world is coming to an end by a large apocalypse. Casey questions why Nix doesn't just warn the Earth, to which he replies that what will happen will happen only on Earth, while Tomorrowland will survive the destruction. Casey questions why couldn't humanity of Earth come to Tomorrowland, but Nix refuses to let them, saying that humanity will mostly likely destroy Tomorrowland like they did to Earth. Casey refuses to believe Earth will end, and the future slightly changes as a result, a fact that Frank glimpses and tries to tell Nix about it, but Nix refuses to listen and orders him and Casey to be arrested instead.
Confession and The Fight
- “Let's imagine. If you glimpsed the future and were frightened by what you saw, what would you do with that information? You would go to...who? Politicians? Captains of industry? And how would you convince them? Data? Facts? Good luck. The only facts they won't challenge are the ones that keep the wheels greased and the dollars rolling in. Now, what if...what if there was a way of skipping the middleman, putting the critical news directly into everyone's heads? The probability of widespread annihilation kept going up. The only way to stop it was to show it, to scare people straight. What reasonable human being wouldn't be galvanized by the potential destruction of everything they've ever known or loved? To save civilization, I would show its collapse. But how do you think this vision was received? How do you think people responded to the prospect of imminent doom? They gobbled it up, like a chocolate éclair. They didn't fear their demise, they repackaged it. It can be enjoyed as video games, as TV shows, books, movies. The entire world wholeheartedly embraced the apocalypse, and sprinted towards it with gleeful abandon. Meanwhile, your Earth was crumbling all around you. You've got simultaneous epidemics of obesity and starvation! Explain that one! Bees and butterflies start to disappear, the glaciers melt, algae blooms all around you, the coal mine canaries are dropping dead, and you WON'T TAKE THE HINT! In every moment, there is the possibility of a better future, but you people won't believe it. And because you won't believe it, you won't do what is necessary to make it a reality. So you dwell on this terrible future and you resign yourselves to it, for one reason: because that future doesn't ask anything of you today. So, yes, you saw the iceberg and warned the Titanic, but you all just steered for it anyway, full steam ahead. Why? Because you want to sink. You gave up. That's not the Monitor's fault. It's yours.”
- ―Nix, revealing he has given up to Frank, Casey and Athena
Later, Frank, Casey and Athena discover that Nix's monitor has a side effect: when it utilizes tachyons to obtain information about the future, it introduces a backfeed into their flow, thus making the future it shows all the more likely, creating a self-fulfilling prophecy; therefore, destroying the device can avert the apocalypse. The trio then go to see Nix again, only to see Nix prepare to deport them to an uninhabited island. The trio try to tell Nix what they have found out, but Nix refuses to listen, claiming that it won't make any difference.
In a two minute monologue, Nix reveals that he created the Monitor to broadcast the warning of the world's end to humanity, but instead of doing anything about it, humanity accepted what they saw, gave in, and repackaged what they saw into media, seeming to care only for the here-and-now, never willing to consider what their actions could mean for the future. As Nix speaks his monologue, it becomes apparent to the trio that Nix himself has given up and actually intends to allow the apocalypse to destroy Earth, and thus allow Nix to build a new world in his own way.
After Nix reveals the truth, he tries to send Frank, Casey and Athena into the portal that will take them to the uninhabited island, but the trio resist.
In the ensuing fight, Frank tries to use a bomb to blow up the machine, but the bomb goes off outside the portal and the explosion pins Nix's leg under debris. Nix tries to kill Frank with a plasma gun, but is stopped by Athena who takes the blast; her self-destruction results in the destruction of the Monitor. The Monitor's remains fall on Nix, killing him.