Disclaimer: The ccharacters, locations and games in general are not in my possession and are owned by Sega.
Shadow and Rouge were on a mission in South Island. G.U.N. had reports of Dr. Eggman's robots attacking. Sonic and his friends were out on a vacation, leaving G.U.N. to protect Cebtral City. Shadow was rushing through Green Hill, destroying all the robots in his way. Rouge was flying right behind him.
"Wait up, Handsime. Not all of us are as fast as you." The flirty bat said. Shadow just scoffed, "If you can't keep up, you better start training harder." All the robots in the area were gone. Rouge pulled out a little device that brought up a hologram of South Island. "According to Commander Towers, there have been strange energy readings appearing in the Marble Palace. It's even stronger than a Chaos Emerald. They want to see if they can use it for a new defense system to protect the city from the old goat of a scientist." Shadow replied, "Something that won't slack off on a vacation like Sonic." Rouge turned off the hologram. "Too bad the knucklehead didn't go with him. Otherwise I'd have a pretty new jewel in my collection."
They finally arrived at the Marble Palace. They entered in. Shadow looked around. "Why an idiot would build a palace ontop of molten lava is beyond me." They then saw a giant robot, probably Eggman's, searching for the power source as well. Rouge said, "I've got this." She blew a kiss to the robot and he got dazed with love. Shadow would never understand how she did that to a robot, but that didn't matter. He pulled out his Chaos Emerald and unleashed a Chaos Blast. The robot did not last long. The two agents continued.