Dr. Eggman discovers that the last two Chaos Emeralds (Cyan and Yellow) are located inside a huge Metarex fortress. The Crimson Egg and the Blue Typhoon arrive on location at the same moment. Eggman suggests Sonic to put their efforts together in order to enter inside the fortress. His plan: a little group will enter first and disconnect the fortress' security system, so the other ones could penetrate. Eggman sends Shadow and Rouge while Chris volunteers to accompany them. They enter with the help of Chaos Control. Rouge tries to get away from Shadow and Chris to get the Chaos Emeralds for herself. She reminds Shadow of the ARK and Maria, which causes Shadow to drop his guard as he has a sort of 'meltdown'. Rouge tries to escape, but is ambused by a Metarex. Shadow saves her and tells her not to run off. Chris finds the control room and they succeed in their job. Sonic & Knuckles penetrate in the fortress aboard the X-Tornado, Amy & Cosmo follow them and Eggman, Bocoe & Decoe are right behind. However, Eggman secretly installed a special device on each ship and he can take control of Sonic and Amy's ships. Eggman almost succeeds, but Sonic finds the emeralds first. The only thing: he is welcomed by an entire army of Metarex, led by Dark Oak, the Metarex leader, and the battle is about to begin. (thetvdb.com)