Sonic and Mega Man are meeting again. But this time, it's far more deadly than either Sonic or Mega Man could have imagined. Everything robotic is turning evil, due to one mastermind. A single virus is spreading throughout both worlds, helping Dr. Wily in his plots to take over the world. As Sonic and Mega Man find each other again, will it be a happy meeting, or will every single robot, including one of the heroes, fight to the death?