Avatar: The Last Airbender – The Rift

Avatar Aang asks his friends to help him honor Yangchen’s Festival – an extremely sacred Air Nomad holiday that has not been held in over a hundred years.
However, cryptic visits from the spirit of Avatar Yangchen herself lead Aang to discover a jointly owned Fire Nation and Earth Kingdom refinery – operating on land sacred to the Airbenders! Is this the cause of the pollution Aang finds there, or is something more mysterious happening?