Avatar fans can look forward to a fourth film after all, with James Cameron revealing that the third sequel in the 3D extravaganza will actually take the form of a prequel.



Only last week producer Jon Landau claimed that he and Cameron would be working on the next two films back to back, but suggested that there were no plans for a fourth episode. Clearly, that has now changed.



"I have an idea for a fourth," says Cameron. "I haven’t really put pen to paper on it, but basically it goes back to the early expeditions of Pandora, and kind of what went wrong with the humans and the Na’vi and what that was like to be an explorer and living in that world."



“In the first film, we’re dropping into a process that’s 35 years in to a whole colonisation," he continues. "That will complete an arc and if that leads into more, we’ll start, not imitating Star Wars , but it’s a logical thing to do because we’ll have completed the thematic arc by the end of three."



"The only thing left to do is go back to see what it was like on those first expeditions and create some new characters that then become legacy characters in later films. It’s a plan.”



As for the workload involved, Cameron has at least managed to streamline the creative process, with the next two (or three) films unlikely to be such a Herculean undertaking.



"We’ve spent two years refining the whole pipeline," he says. "It was a hideously complex process to make that film and a lot has been said about that, but we don’t want it to be done in the same prototypical way as the first one, we want it to be a much smoother workflow just for creativity reasons.”



Avatar 2 will arrive at some point in 2015.