The sequel to the record-shattering Sonic the Hedgehog and Mega Man crossover is here! You saw what happened when "Worlds Collide!" Now brace yourself for when WORLDS UNITE!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 the coming tide of darkness!This volume collects WORLDS UNITE parts 1-4.

SONIC and MEGA MAN scribe IAN FLYNN has been the chief writer for Archie's popular and record-setting SONIC THE HEDGEHOG comic for more than five years, including the headline-grabbing SONIC: GENESIS storyline and graphic novel. He is the main writer of its sister titles SONIC UNIVERSE and SONIC BOOM and their accompanying graphic novels, and is also the writer of Archie's MEGA MAN series, another critical and popular hit. Flynn also helmed the historic meeting of Sonic and Mega Man in the popular SONIC/MEGA MAN: WORLDS COLLIDE and WORLDS UNITE storylines, and wrote the critically-acclaimed NEW CRUSADERS series, Archie's return to the superhero genre.