The Chemical Plant Zone was built by Dr. Julian Snively, the renegade G.U.N. scientist, following Ivo Robotnik's coup d'état and successful takeover of Mobotropolis, though he later claimed he had been forced to construct it. (SSD: #12)
After defeating Dr. Eggman and his assistant, Dr. Julian Snively, at their base on South Island, Sonic the Hedgehog chased the two mad doctors down to Westside Island, where he teamed up with his new sidekick and best buddy Miles "Tails" Prower as well as the Knothole Freedom Fighters. They arrived in Chemical Plant Zone after passing through Emerald Hill Zone in their efforts to defeat the mad doctors, whose goal on Westside Island was major construction and refinements as part of their plan for world domination. From here, they chased them down to Aquatic Ruin Zone. (VG: StH2, SSD: #12)
- From a reader's perspective, this picks up from where the original Pre-Super Genesis Wave continuity left off.
Some time later, the Unity Engines caused the zone to merge with a federal prison on Earth 20XX. As a result of this, Xander Payne discovered his ability to generate Genesis Portals and escaped while the guards attempted to contain the other prisoners. These events were later undone when Xander prevented Sigma from ever enacting his plan by attacking him in the past. (SSD: #12; MM: #50)