 Japanese title card · “The Battle on the Ice Palace” | |
| Series | Sonic X (ソニックX), TMS Entertainment |
| Season | Season 3 (2005–2006) |
| Episode | Season 3, episode 5 · no. 57 of 78 |
| English title | “A Chilling Discovery” (4Kids) |
| Japanese title | アイスパレスの戦い (Aisu Paresu no Tatakai, “The Battle on the Ice Palace”) |
| Japan | Not shown on Japanese TV until 1 April 2020 (Kids Station) |
| First aired (US) | 8 October 2005 · 4Kids TV (Fox) |
| Directed by | Kazunori Tanahashi |
| Written by | Masahiko Shiraishi |
| Storyboard | Seiji Okuda |
| Previous episode | An Enemy in Need (S03E04) |
| Next episode | Desperately Seeking Sonic (S03E06) |
Metarex SagaIce planet
A Chilling Discovery is episode 5 of Season 3 of Sonic X and the 57th of the anime’s 78 episodes. In Japan it is called “The Battle on the Ice Palace” (アイスパレスの戦い). It premiered in English: 4Kids aired it on 4Kids TV (Fox) on 8 October 2005, after a French TV debut on 15 March 2005, while Japanese TV only showed it on 1 April 2020. It was directed by Kazunori Tanahashi and written by Masahiko Shiraishi.
Synopsis
A day later, Chris’ new tracking program picks up a Chaos Emerald on a frozen planet – Breezer in Japanese sources, Breezy in the English version – and the Blue Typhoon heads there with Eggman’s Crimson Egg close behind. A Metarex attack sends the ship crashing onto the ice, so Sonic, Chris, Knuckles and Cosmo go after the Emerald in the X-Tornado.
The snowfields are crawling with Metarex soldiers, and the crew has to fight its way across the ice, where Sonic finds his footing anything but reliable. Rouge, now travelling with Eggman, is racing them to the prize.
The trail ends at an ice palace where the Metarex have been doing research, and the Emerald is inside, locked in a block of ice. A stronger Metarex draws power from it until Cosmo works out how to beat it with a laser, and the Blue Typhoon’s beam finishes the job. The Planet Egg returns and the snow melts away. Rouge snatches the gem – and it crumbles in her hand: a Metarex fake all along.
Key Moments
- Chris’ new program tracks a Chaos Emerald.
- The heroes fight through the Metarex on the ice.
- The Emerald in the Ice Palace turns out to be a fake.
Trivia
- Masahiko Shiraishi’s first Season 3 script; he wrote six episodes of the season.
- On home video: the The Complete 5th Season DVD set (2006); and Discotek’s Sonic X Collection 2 (2016) and complete-series Blu-rays.
Watch the Episode
The full 4Kids English episode, uploaded by TMS Entertainment’s official “Anime! on TMS” YouTube channel (checked 6 November 2026).
Part of our Sonic X Season 3 guide. See the Sonic X series page for the cast, theme songs and home video.
Sources: titles, credits and air dates from Wikipedia’s list of Sonic X episodes and Sonic Wiki Zone, cross-checked with each other and with Luke’s original Sonic Scene episode table; synopsis written for Sonic Scene from the episode, Wikipedia’s summary and Sonic Wiki Zone’s plot notes; title card and screenshots via Sonic Wiki Zone, copied to our media library.