Even if you haven’t seen the movie by now, you’ve probably seen the pointy-headed crystal skull, and in this movie we all learn exactly where that skull came from: outer space. (Or another dimension, but same thing, right?) Unfortunately, every Indiana Jones movie so far has been about the power of religious artifacts. Not only are the skull’s powers nebulous (it stops ants? It makes you go crazy if you look at it? It’s a magnet?), thereby making it a terrible MacGuffin, it calls into question the God-given power of every artifact Indy’s ever seen in action. Were the Shankara stones space rocks? Was the Ark radioactive? Was the Holy Grail a life-extending alien beverage container? Everything we know has been cast into doubt — now imagine how Indy feels, after spending a lifetime chasing this stuff.

— "You Are Now Leaving Indiana" from Television Without Pity