Daring Do and the Cave of Skulls

Daring Do tried to flap her wings to slow her down, but she hurt one when she made all those mistakes reciting that tune. She just spread them out, and she kept falling. So she cringed, and put her front and back hooves on a wall in that tight squeeze, pushed... and stopped. She then started putting one back and one front in front of the other... until she reached a fiery floor. And heard a roar. Daring couldn't tell who it was, but she heard, "WHO DARES TO DISTURB ME? WHAT DO YOU WANT, PONY?" the pony shivered, and ran. Looking everywhere, there was no skull that looked like the one in the photograph. However... "am I in Tartarus?" Daring Do asked that booming creature, perhaps the one from before. "NO. I CANNOT TELL YOU WHERE YOU ARE, BUT TARTARUS IS WHERE YOU AREN'T." it said.

And so Daring decided to look for something else that could help her. She looked at the walls, with some little gray cylinders lined up perfectly.
With straight bumps, it seemed so familiar. She pushed on one part... And it went inward, and a bit more light was in there. A secret place. She walked up the stairs... and then came face-to-face with TIREK. "PONY." he bellowed. That "pony" looked down. There was something in his hands...