Hush (Buffy the Vampire Slayer)
A group of silent pale demons known as the Gentlemen have taken the voices of everyone at Sunnydale in a box. Once the Scooby Gang woke up, they learned that they can’t speak. Giles does a slideshow explaining who the Gentlemen are and that they kill people who lost their voice. They had stolen the voices so they won’t get killed by someone screaming.