Sonic the Hedgehog visited Argentium while he was traveling through space, hoping to find a way to return to Mobius. However, when he arrived he was surprised to learn that he wasn't the only Mobian there: Tails' parents Amadeus and Rosemary Prower were also guests of the Bem, having been brought to Argentium by the Bem scientist Ceneca 9009. Because Ceneca 9009 had De-Roboticized Amadeus with her outlawed Robotizer machine, she was sentenced to life in prison. Sonic agreed to help her and the Prowers, but the only ship they were able to obtain could only take one of them back to Mobius. Despite his wish that one of the Prowers go, Sonic was the one, and he traveled through the artificial wormhole adjacent to Argentium.