|This location exists primarily or exclusively within the Sonic X continuity.|
Information in this article may not be canonical to the storyline of the games or any other Sonic continuity.
With Rouge suspected of having returned to her ways of thievery, a false Chaos Emerald was announced to have been put on display in the Smithsonian Institute in order to lure her out. That night, Captain Westwood, Knuckles the Echidna, Sonic the Hedgehog, and Topaz awaited Rouge's arrival.
When Rouge showed up, Knuckles demanded she returned the Master Emerald she had stolen. When she denied doing that though, a fight broke down until Knuckles smashed Rogue into the building, upon where they discovered the Rogue Rouge, the one who had been framing Rouge. Sonic, Knuckles and Rouge subsequently fought the robot until Dr. Eggman arrived to steal the "Chaos Emerald". While Sonic and Knuckles destroyed Eggman's robot and retrieved the Moon Emerald and Master Emerald, Rouge destroyed her robot double.
- The Smithsonian Institute is based on the real-life location with the same name.