Secret message key
In Chapter 1, just after you repair the claw for the tram, hit your objective finder. Follow the blue line into the hallway where you need to go. Stop as soon as you enter the hallway, and look up at the catwalk above your head; ignore the alien for now. Walk until you find the first corridor on the right. Walk in there to see writing in an alien language all over. Look down to see a message in English that reads "Don't listen to their lies, read what they're really saying." Keep reading to find a key that shows the alien language, and below that English letters from A to Z and 1 through 0. Although not everything will be legible, you should be able to decipher enough to understand what is written.