The third Avatar chapter erupts with volcanic world-building and thunderous action yet remains a vast, dazzling spectacle in search of an emotional arc

On and on and on it goes. The planet-sized movie franchise of Avatar continues to spin massively in the cosmos – yet without affecting the tides in any other world. Maybe Avatar is the cosmos and its originator James Cameron is the new L Ron Hubbard; the creator, or rather prophet, of a new belief system involving big blue creatures with pointy ears that flap and twitch when they talk, to whom we will all one day be required to bow down when they float past. And while the rest of the cinema industry has quietly abandoned 3D without ever quite admitting it, theatres showing James Cameron’s giant new three-hour hunk of nonsense are still handing out the 3D specs to the customers.

The first film was about human invaders seeking to exploit and colonise the weird tall blue Na’vi people in another galaxy for their mineral resources by piloting “avatar” replicants into their midst. One of these pilots was Cpl Jake Sully, played by Sam Worthington, who fell in love with Neytiri, played by Zoe Saldaña, and stayed behind as a Na’vi – thus infuriating his commanding officer, Col Miles Quaritch, played by Stephen Lang, who since then has died in battle but is now resurrected as a Na’vi avatar, looking scarily as if Vinnie Jones had joined the Blue Man Group. Quaritch’s teen son Spider (Jack Champion) has turned against him and lives with Jake and Neytiri as their adoptive child. In the second film, the Na’vi people found a new world of water. Now in this third film they face the new element of … fire. For the proposed fourth and fifth films, they will presumably tackle earth and wind.