Doctor Eggman detects unusual energy readings in his base when Geno emerges from a rift and steals a Chaos Emerald. After a brief clash with Metal Sonic, Eggman realizes Geno is from another reality and wants to use the Emerald's power to temporarily replace the unstable Zero Point, the energy source behind his operations. Geno promises Eggman a powerful position in a future reality he plans to reshape, and after Eggman demonstrates the Emerald's power in Reality 266's Shattered Coast, the two form an alliance.

Meanwhile, Tails discovers Eggman and Geno's scheme while investigating strange energy readings. He follows them through a rift into another reality but becomes trapped because Eggman has modified the portal so biological beings can only travel one way. Sonic, Knuckles, and Shadow respond to Tails's SOS signal, but they refuse to enter the rift due to the risk of becoming trapped themselves.

To solve the problem, Tails reprograms three robots he found in Eggman's convoy and models them after Sonic, Knuckles, and Shadow using their biodata and personalities. After some humorous interactions with their robotic counterparts, the heroes send the robot team through the rift to Shattered Coast, where they will fight Eggman and Geno in their place.