As you enter the cafeteria at the beginning of the day, you become frozen in fear at what you see. A friend of yours. A fellow crewmate. Well... What used to be her, at least. And only the bottom half of her, pooled in blood, "Oh... Oh my god...!" You run up to the body as if there's anything you can do. You scream. You cry. Who did this?! How could this happen?
As the other crewmates on the ship file in, they are just as horrified, reacting in similar ways to you. They all appear devastated. One... Is a liar. One of them is a murderer.