Newtrogic High Zone is the main setting of Knuckles' Chaotix. After completing introduction level Isolated Island, Newtrogic High Zone becomes the hub world of the game, where the player can choose the combi partner (person who is trapped in a Combi Catcher) and level.
In the English storyline, it is located on Carnival Island, which Knuckles patrols before its grand opening day—though Dr. Robotnik sets his sights on its "Power Emerald" which supplies electricity. In the Japanese storyline, Dr. Eggman discovered that an unnamed island rose from the sea, and built Newtrogic High Zone on the island after he discovered the Special Ring, a ring that on inner part has the ancient language of Knuckle's people. The Chaotix Crew also arrived of their own accord: Vector the Crocodile believes the island's rise is a miracle of God, Espio the Chameleon goes to investigate, Charmy Bee (or "the fastest insect in the world") travels to the island to search for a new flower, Mighty the Armadillo happened to come across the island while adventuring, and Knuckles the Echidna comes because he noticed and fears it is connected to the Floating Island. Heavy and Bomb defected from Robotnik and decided to help the Chaotix. After the Chaotix (except Knuckles) arrive on the island, they are captured in Robotnik's Combi Confiner. After Knuckles started to explore the island, he came across Espio, who was trapped in one of the machines. Using the power of his ring, he freed Espio and tried to obtain the Chaos Rings and stop Robotnik.
After completing all the "attractions", Metal Sonic comes out and fights the Chaotix. After being defeated, he flees to Robotnik, who escapes as Metal Sonic Kai suddenly appears. But despite his great size and power, he is defeated. If the player manages to collect all the Chaos Rings, the island will presumably be restored, and even Sonic and Tails visit on the Tornado. If the player fails, Metal Sonic Kai will appear, overlooking a burning area (possibly Newtrogic High Zone).
- The artwork of Newtrogic High Zone (see above the article) is featured at the Sega intro in earlier prototypes of Knuckles' Chaotix, but it has been later replaced with normal space background in final version of the game.