Moment From Buffy the Vampire Slayer S04:E10

Stake Them
When The Gentlemen steal the voices of the residents of Sunnydale certain hand gestures are mistaken for others when used out of context.
The entire town of Sunnydale goes silent when a group of fairy tale demons called The Gentlemen appear and steal everyone's voices. Without being vulnerable to the one thing that can kill them (a human scream) they are free to steal the hearts of seven people. Buffy and gang must solve the mystery and overcome the bad guys without being able to discuss anything.
Tags: The WB, high school, monster, magic, vampire, anti hero, supernatural, chosen one, female protagonist, apocalypse, teenager, vampire slayer, fighting supernatural