The large sandstone door is closed, sealed, and engraved with ancient hieroglyphics.
> examine seal
The seal holds the door shut forevermore. It appears to be made of unobtanium.
> read hieroglyphics
They read, from left to right: "Bird Looking Left, Stick Figure Holding Lantern, Three Reeds, Rectangular Thing With Fangs, Something That Looks Like Cthulhu, Stick Figure Being Violated, Potato With Letters On It, Dog Passing Water."
> speak "friend" and enter
This ain't no three-volume novel, fatcakes.
> fire a hadoken
Yeah, so you thought killing the Grue King gave you enough XP to gain ten levels of Black Magery? You must've miscounted, poindexter.