You can make yourself absolutely silent, you simply cannot be heard. You can turn this power on or off as a 0-shot action.
This changes how you Sneak - as long as you are under cover, you are automatically successful.
You can force this power upon another with a touch - including any melee attack. Anyone you touch must make a Willpower roll matching your Powers in order to make a sound for the rest of the Sequence. This prevents them from calling out or using HocusPocus limitation or a Restriction involving sound as well as Scream or other sound-based powers.
Taking this schtick several times gives you a zone of silence around yourself, with a radius equal to your Magic in meters times the number of extra schticks.