They descend suddenly from the stars, in monumental ships like floating cathedrals. They are touched by a dark and terrible force from beyond our reality, silent but for the one note they emit that freezes all motion. Their mission: to drain the Earth of all its kinetic energy and leave it a lifeless husk. They never expected anyone could escape their song -- but the Flash was in the Speed Force when they struck, and Aquaman was in the deepest ravine far below the ocean's floor. These heroes have little in common. They've rarely even fought side by side without their fellow Justice League members. Now they must find a way to work together against impossible odds to save the world and the people they love.