Super-villains HEATWAVE and CAPTAIN COLD don't like the FLASH, but they don't like each other either! They face off in a climate-changing smackdown that could spell disaster for Earth's ecosystems. The FLASH tries to take the foes one-on one, but ends up encased in arctic ice. Unable to move, FLASH watches as HEATWAVE turns up the threat level by melting the frozen seabed . . . a sea full of explosive methane gas!