Eggman's newest fiend, the Chaos Emerald absorbing Chaos, is growing stronger and more powerful. It's up to Sonic and Knuckles to stop this menace before they destroy Station Square. Then, who or what is Shadow the Hedgehog? Eggman discovers the secret lab of his grandfather, Professor Gerald. Freeing the sleeping Shadow, Eggman uncovers his grandfather's plan to destroy the world!
