"A Chilling Discovery" is fifty-seventh episode of the anime series, Sonic X. It first aired on 15 March 2005 and 8 October 2005 in France and the United States respectively.
- Sonic the Hedgehog
- Miles "Tails" Prower
- Knuckles the Echidna
- Amy Rose
- Cream the Rabbit
- Christopher Thorndyke
- Dr. Eggman
- Rouge the Bat
- Metarex Gigatail (Only appearance)
- Metarex Crystal (Only appearance)
- Metarex Trooper (First appearance)
- "Gotta Go Fast" - Opening theme (USA and CAN)
- "Sonic X" - Opening theme (AUS, NZ and UK)
- "Gotta Go Fast" (shortened) - Closing theme
With the help of Chris' new program, the Blue Typhoon spots a Chaos Emerald on Planet Breezy. Followed by Dr. Eggman's Crimson Egg, the Blue Typhoon approaches Planet Breezy, but it is attacked by a Metarex robot and it crashes on the planet. Sonic, Chris, Knuckles and Cosmo decide to go get the Chaos Emerald with the X Tornado because the Blue Typhoon is damaged. Rouge is also on her way for getting the Emerald before Sonic.
Everybody has to fight the Metarex before reaching an ice palace, where the emerald is supposed to be located. Sonic's group find it, but it is sealed in a solid ice block. A more powerful Metarex appears, the Metarex Crystal, which takes power from the emerald to become even stronger. A fight engages and Cosmo finds the way to defeat it with a laser beam. The laser from the Blue Typhoon defeats the Metarex Crystal. The Planet Egg gets trashed into the planet and the snow disappears. Knuckles finds the Chaos Emerald but before he gets it, Rouge steals it. However, Tails discovers that the Emerald was a fake. Rouge soon discovers the Emerald is not real and it crumbles in her hand and she becomes angry.
- When Knuckles climbs up the X Tornado, his left arm is colored peach instead of red.
Title in other languages
|Japanese||アイスパレスの戦い||The Battle on the Ice Palace|
|French||Combat au palais des Glaces||Combat Palace of Mirrors|
|German||Emerald im Eis||Emerald in Ice|
|Italian||Una raggelante sorpresa||A chilling surprise|
|Spanish||Batalla en Ice Palace||Battle in Ice Palace|
|Polish||Walka w Lodowym Pałacu||Fight in the Ice Palace|
|Russian||Битва в Ледяном дворце||Battle in Ice Palace|