James Cameron is willing to admit more than a touch of performance anxiety the second time around.

His last film as a director, Avatar, scored nine Oscar nominations and grossed more than $2.7 billion around the globe – a record-setting amount of money that ushered in a new era of 3-D blockbusters.

But Avatar experienced a fairly torturous journey to screen, with studio bosses second-guessing Cameron’s technological demands, cost over-runs, and production delays. Its distributor, Twentieth Century Fox, almost backed out on a deal to make the movie at all.

Six years later, however, and Cameron is in the midst of ironing out the kinks on screenplays for second, third, and fourth installments of Avatar. “I’m in the process of doing another pass through all three scripts right now,” Cameron told EW during a recent phone interview. “Just refining. That’s in parallel with the design process. The design process is very mature at this point. We’ve been designing for about a year and a half. All the characters, settings and creatures are all pretty much [set].”

So given that the hardest parts of research and development are already squared away, has the prospect of bringing a new installment to the screen gotten any easier this time around?

“No,” Cameron said, laughing. “Because you have to challenge yourself. Obviously, expectations are going to be very high on these films, especially on Avatar 2, to make sure it wasn’t just some big fluke the first time. So we’ve got to deliver. I’ve created a nice rod for my own back, so they say.”