In "A Caress of Twilight", Merry develops her second hand of power. Merry must protect Maeve Reed, an exile from the Seelie court, from the Nameless (when the fey came to America they gave up their most deadly magicks; the Nameless was made up of those magicks). During the battle, she charges the mass of energy and puts her left hand out; she feels her blood begin to boil, and large gashes appear on the enormous mass of magic. All Merry has to do is think "Bleed" (occasionally "Bleed for me!"), and the person (or things) bleeds. This is the development of the Hand of Blood.