Naughty Dog has released the first in a series of videos that chronicle the development process of The Last of Us. The first episode, entitled Hush, talks about the fungus-infected humans Joel and Ellie will encounter.

While they may look and act like zombies, they are definitely not undead. Hush reveals the origins of these poor people who were exposed to the fungus and then turned into monsters.

More development videos are on their way up until The Last of Us’ June release. Naughty Dog plans to include more behind-the-scenes videos of the game’s development on the disc as well.