You place a curse upon a target character.
The target is magically rendered mute. They are unable to cast Spells and cannot speak or make any verbal sounds in-character. They can still speak out-of-character, especially to call for help in case of a safety situation or emergency. They can still make noise in-character (such as by clapping or banging a hand against their armor), but they cannot speak or make any noises verbally.
The effects of this ritual last until the next sunrise, until you choose to remove it, or until the curse is broken.