When Sonic pursues Doctor Eggman through space and transforms into his superhuman form, the villain springs a devastating trap—unleashing a weapon that not only strips away Sonic's power but fires a catastrophic beam toward Earth itself. The blast awakens Dark Gaia, an ancient destructive force slumbering beneath the planet's surface, shattering the world into disconnected fragments while cursing Sonic with a nocturnal transformation that grants him tremendous strength at the cost of his speed and humanity. Stranded on a ravaged world, Sonic encounters Chip, a peculiar creature with no memory of its own past, and the unlikely pair embarks on a globe-spanning journey to locate the scattered Chaos Emeralds, reverse the planetary devastation, and uncover the truth behind Sonic's monstrous affliction. Their quest to restore balance and rejoin a broken world becomes inseparable from the race to stop Dark Gaia from consuming what remains of civilization.