The epic battle against Mongul begins here, as the true origin of the Black Mercy is revealed! The Green Lantern Corps find itself pitted not only against Mongul to save Sodam and Arisia, but an entire planet made of Black Mercys that seem to be under the control of a quite possibly darker and more disturbing force. This creature the Corps will come to fear is known simply as Mother Mercy — and it has no plans of showing any now or ever.