The Freedom Fighters are in the Hill Top Zone when they are suddenly interrupted by an invasion by a group of Penguinator Badniks. With some effort, the heroes beat the Badniks, but Sonic is confused as to why the Floating Island Badniks were on Mobius. Porker Lewis directs Sonic's attention to a massive portal to the Ice Cap Zone, from which more Penguinators are pouring out. The fight begins again, but Sonic wishes to tackle the source and hops through the gateway. In the Ice Cap Zone, Sonic finds Knuckles the Echidna fighting more Penguinators and Star Pointers and joins in. After an argument, the make a temporary truce to help each other destroy the technology responsible for the portal, unaware that Doctor Robotnik is watching them.
Hurtling through the Zone, the heroes spot a building that wasn't previously there. Sonic smashes his way in and the heroes are greeted by Robotnik. The dictator quickly traps them in a energy forcefield and explains that his Inter-Zone Technology will soon be used to spread Badniks rapidly throughout the entire planet. Knuckles burrows his way through the unprotected floor, giving them a way out. While the echidna destroys the last of the Badniks, Sonic wrecks the technology as Robotnik escapes. Sonic then returns through the portal with the rescued organic batteries before the gate can close. Back on Mobius, Tails fears that a flurry of snow is another of Robotnik's plots, but Sonic reminds him it is Christmas.
- Penguinators and Star Pointers make their first appearances.
- The Hill Top Zone looks nothing like its previous rocky appearance, instead resembling the Emerald Hill Zone.
- This story doesn't seem to fit into the StC timeline very well. Knuckles went to the Carnival Night Zone immediately upon his return to the Floating Island in Issue 39, and by all appearances, stayed there until the end of his "Carnival Night Conspiracy" story. Then, in Issue 47's "Mystery of the Sandopolis Zone", Knuckles indicated that the only reason he hadn't disposed of the Death Egg before then was his run-in with Marxio Brothers, indicating he was heading straight there following the end of "Carnival Night Conspiracy". Thus, exactly where or how "Ice Cap Attack" fits in is unclear——despite the fact that Issue 47 also sees Knuckles making a reference to its events.