MTV News: It doesn't matter if you're doing something like "Machete" or a "Spy Kids" movie, you've always got some tricks up your sleeve. How are you going to wow us with "Spy Kids 4"?

Robert Rodriguez: Man, I can't say everything just yet! There are going to be some things you'll see and go, "Hey, why didn't he tell me that?" You know, we did three of these movies, and then stopped because the kids were getting older. But families still come up to me and say they're watching them, so 10 years later, it felt right to do another one. I got the idea when I was making "Machete" and Jessica came over to my house for lunch with the kids, and she was bringing her daughter out of the backseat. But her diaper had exploded and the kid had made a huge mess and just seeing Jessica dressed up, so beautiful and glamorous, but having to deal with this baby with an exploded diaper, I just thought, "I'd love to see her as a spy mom." I wrote it around her and figured she'd have two new stepkids who don't think their mom is cool, but she's really a spy and their dad plays a spy hunter on a TV show and doesn't know his wife is a spy. There's a robot dog and a spy baby and a new villain, played by Jeremy Piven. And I was looking at my own kids and how quickly time is going by and how you wish you could freeze a moment, so the villain is the Timekeeper, and he is taking time from people and the world is getting faster.