Shadow and Pico are at it again in another epic adventure!! When Pico suddenly falls victim to a corrupting virus, he and Shadow find out that Sonic.exe has teamed up with Infinite and Mephiles to create a dark plague that would kill Pico in 30 days if Sonic.exe and his allies aren't killed within that time. With a time limit imposed and a need for revenge, he and Shadow embark on a quest to save him from death. It's time to get gunslingin' with Shadow and Pico once again!!