I thought it was absolutely appropriate to have paranormal aliens. I mean look at X-Files, one episode they are chasing a spirit, the next episode they are chasing bigfoot, the next episode one of them is being abducted by aliens. I still don't really understand the apprehension to the extra-terrestrial plot. I thought the film suffered a bit by showing them too much, but the plot itself was very well done I thought, and appropriate to the Indy series.