At least, the minions of Nephren-Ka are evil, and they're looking to bring the long-dead pharaoh back to life. You investigators will have to make sure that doesn't happen. It's what you're tasked with doing in Omens of the Pharaoh, which is the new expansion for Elder Sign, available now.
From the post:
You’ve heard that the desert’s heat can play some terrible tricks on the mind. You desperately hope that the scene in front of you is one of those tricks, an illusion you can simply deny and forget. The air swims and shimmers all about the edges of your vision, as the sands before you bulge with the subterranean passage of innumerable slithering abominations. Spindly horrors with dozens of chirping, chittering mouths skitter between the yawning crypts that line your path on either side.
The entrance to the Lightless Pyramid is swarming with the awful minions of Nephren-Ka, but thankfully their attention is elsewhere. A booming howl, equal parts triumph and pain, abruptly bursts from every gaping passageway that leads deep within the ruins, and the gathered throng of monstrosities rushes underground. They vanish beneath the sand, and, in the strained and uncomfortable silence that follows, you almost convince yourself that it had been a trick of the heat. Almost, but not quite. You brace yourself for the descent even though you fear that you are too late, and Nephren-Ka has truly returned to Egypt...