Dark forces have come together in the far future! The vicious conqueror Sigma has cheated death again and escaped the justice of X and the Maverick Hunters. He's crossed space and time to join forces with Zavok and the malicious Deadly Six of Lost Hex. Sonic and Mega Man could save us - but they've gone missing! Now the Freedom Fighters of Sonic's world and the Robot Masters of Mega Man's world must take up the fight to save their heroes and stop...