In the world of Sonic, a distress signal from Earth calls for Sonic and his friends to jump into action as the Black Arms arrive after 50 years. Meanwhile, Shadow the Hedgehog has amnesia after his final attack on the Metarex, and has a keen interest on the Black Arms who shares secrets about Shadow's past. Unsure of who he is, he must find the right path in order to learn more about himself while dealing with the leader, Black Doom.
