While walking through town you see someone with a white cloak and fae speed sneaking around, a glint of light from the blade is all you see as the person near you drops to the ground in a bloody heap. The person already gone in a flash, but they made one mistake as a little very faint trail of blood leads right to them. You follow in the moonlight and see them cleaning their blade in a town alley way.

(If you want to know what type of fae this is read the "Throne of Glass" book series by Sarah J. Maas. Based off that series highly except for characters and locations!)