The Creepy, Real Science Behind 'The Last of Us'

What's This?

By Chelsea Stark2013-07-26 11:00:00 UTC

During the creation of Uncharted 2, Naughty Dog Creative Director Neil Druckmann watched Planet Earth, the nature documentary series. What was originally just entertainment generated the next idea for Naughty Dog's blockbuster title The Last of Us.

See also: 'The Last of Us' Is Raw, Real and Awesome

In one particular Planet Earth clip, a cordyceps — a parasitic fungus — latches onto ants, infecting them and taking control of their brains. The ants lose control of their bodies and go off somewhere to die. Their bodies become hosts to a massive fungal sprout that shoots out of their heads — once the cordyceps reaches maturity, it sends off spores to infect other creatures nearby.

As the Planet Earth narrator tells it, there are thousands of types of cordyceps fungi, and each specializes in one host species. So Druckmann wondered, what if it could infect us?

Nightmares in Nature

For those who haven't played, The Last of Us, out last month for PlayStation 3, is an action-adventure game set 20 years after infection wipes out much of the United States population. The infection was a mutated version of cordyceps, able to turn people into shambling, thoughtless monsters out to infect others. In other words, a twist on the classic zombie game.

"Everything in survival horror games tries to be creepy on every level, but we wanted to add some color and natural beauty to that," says Druckmann.

The team thought about enemies who looked consumed by the fungi. The game's Clickers are the best example; they've spent so long infected by cordyceps that their heads are nothing but colorful fungal masses.

"If this was grown in nature, you would probably stop to admire it," Drunkmann says. "Instead they are out to kill you. It's a great contradiction to have something so nasty with a gorgeous color palette."

Doing Their Homework

Druckmann and Naughty Dog Game Director Bruce Straley agreed a story idea based in truth made a more compelling game. To prepare for The Last of Us, they spent time researching cordyceps and other real parasites.

"It was all based on the idea that the more numerous a species becomes, the more likely it is to be preyed on by this fungus," Drunkmann says.

The cordyceps isn't the only creepy parasitic predator Druckmann found. He shares a story about a recently discovered wasp in Costa Rica which temporarily paralyzes a spider to lay its eggs on its abdomen. Once those eggs hatch and the larvae is mature, it secretes a chemical that forces the spider to abandon its normal web-building operations, and instead create a cocoon around itself. Once it does that, the spider dies and the larvae consume its body.

"These infected do the things they know how to do but in a really perverted way. Some of the best horror stories always talk about 'a fate worse than death,'" Druckmann says. "Nature is way scarier than anything we could ever imagine."

Another aspect of the Clicker enemies was also inspired by real-world ideas. The enemy gets its name from the clicking sound it makes; the fungal shield has rendered it completely blind, and it uses echolocation to move around and track its prey.

Druckmann says this idea was based on a 20/20 segment he'd seen. In it, a 14-year-old boy blind since birth learned to use echolocation to navigate his world. Apparently, the brain's visual cortex is active even when someone is deprived of sight, so it fills in "pictures" through touch and hearing, allowing the blind and visually impaired to get a better sense of place.

Despite their handicap, Clickers are the most ruthless and frightening enemy in the game, and it isn't long before players will associate a far-off clicking with danger ahead.

Humans: Our Own Worst Enemy

Of course, half the foes you encounter in The Last of Us aren't infected by cordyceps. They are the other people left to survive as modern society crumbles, and most are pretty worse for wear.

Druckmann says the team put a lot of thought into how to write the other survivors, desperate people who'd lived for years fighting off infected and other humans. The main characters, Joel and Ellie, encounter several groups of humans along the way, and usually the results don't go so well.

One of the resources Druckmann studied was the book Polio: An American Story, by David Oshinsky. He learned that as polio ravaged the country in the 1940s and '50s, so did misinformed theories on how the disease spread, including that the lower class transmitted it through unwashed hands. The book also covered different scientists' politically-fueled motivations to complete a vaccine, how they'd perform unethical experiments and test unfinished medicine on their own families in a race to the cure.

He also says The Last Plague, a book about the 1918 Spanish Flu epidemic, was tremendously helpful. One of the most unique flu outbreaks (10-20% of those infected died), the virus killed healthy young adults instead of those with weaker immune systems. The virus hit every corner of the globe, and is responsible for a death toll in the millions.

"It talked about how towns would basically shut down to avoid spreading infection during that time," Druckmann says. "It makes you really wonder, 'What will I do to survive?'"

Image: Flickr, ggallice

Topics: Entertainment, Gaming, Science