In the third instalment of cinema’s shiny blue 3D eco fable, James Cameron drags us to the volcanic badlands to meet the ever so angry Ash PeopleSay what you like about James Cameron, but the man has somehow made three films, umpteen extraterrestrial biomes, and one endlessly grieving smurf wolf pack out of the phrase “don’t touch that tree”. Now, the veteran sci-fi film-maker returns with Avatar: Fire and Ash, the third instalment in cinema’s shiniest blue 3D eco fable. And from a preview of the trailer (to be released before showings of The Fantastic Four: First Steps this weekend) this is going to be yet another jaw-dropping, box-office smashing triumph of elemental, stereoscopic worldbuilding – or possibly a very long and very heavy bioluminescent deforestation story, depending on your point of view. Where The Way of Water took us out to sea to commune with whales who cry in subtitles, Fire and Ash drags us into the scorched heart of Pandora’s volcanic badlands. Here we meet the Ash People – an angry, soot-streaked Na’vi clan who appear to have spent the last two films building up a healthy mistrust of outsiders. Imagine running into the scariest-looking Great Plains warriors Hollywood ever dreamed up, then dipping them in tar and relocating them to Mordor. They ride screaming banshees through smoke clouds, and if the trailer is anything to go by, they’ve had just about enough of Sam Worthington’s Jake Sully, his adoptive family and the entire colonial project of humanity in general. Which is why it’s a little strange to