Talking with hunter zolomon, we both got a killer idea for Austin Powers 4.
Have Scott be the villain and have Dr. Evil captive and Austin Powers must stop him obviously. However, with Scott things have changed and the format has changed from old school spy plots to Jason Bourne/ Mission: Impossible type spy films. So Austin has to get with the times and try to keep up with the advanced and modern age of spydom.
Daniel Craig pops up as Power's illegitimate son who is a current agent and they both work together to stop Scott Evil with many references and jokes to follow.