Chris arrives in Sonic's world as his 12-year-old self. He makes contact with everyone, but Sonic faints shortly after. Apparently, the recent battle tailed him off. Back to Cream's house, Cosmo explains the Metarex goals and the consequences of the planet egg's removal. Cosmo also admits that she's the only survivor from her group, which was eliminated by the Metarex. Everybody (except for Knuckles, who's suspicious of her) agrees that the Metarex must be stopped and they decide to go into space to destroy the Metarex and to find the lost Chaos Emeralds. Luckily for them, Tails has just finished to build his new invention: a big flying fortress called the Blue Typhoon. Unfortunately, his new ship used to be powered by the Chaos Emeralds. Chris thinks that they could use the Master Emerald. Knuckles disagrees, but with some female persuasion, he finally agrees. At the same time, another Metarex is sent to the planet in order to destroy Sonic and the Blue Typhoon. A fight engages between the Metarex and Sonic & Knuckles. With the help of the Typhoon's primary weapon, the "Sonic Power Cannon" ("Sonic Driver" in the original Japanese version), the Metarex is destroyed. The Blue Typhoon takes off, but it is followed by Dr. Eggman and Rouge. (thetvdb.com)