Pentarex
"Imagine two worlds – one called Kab, the other Xibalba – on either side of a great platform, connected by sky and earth, such that if one were to dig deep enough, one would enter the opposing world or if one were to fly high enough, one would eventually touch the ground of that same opposing world. In fact, it is said, the stars above are merely the lights of the opposing world’s souls, souls of our world who have transmigrated to that world after a time in the intangible in-between. Or perhaps the stars are simply the campfires of sojourners in the afterlife.
However, it is said and believed by many that when the time of a worthy one in that underworld expires, when they have successfully passed all the trials of that terrible place, that fortunate one is reborn in ours with their memory of hell wiped clean. Alas, there are many unfortunates who must endure the sufferings exacted upon them by the tyrants of Xibalba and the tyrants never play fair.
Knowing this, in our stories, there have been many who sought to find the secret entrance to Xibalba from Kab to free their loved ones from torment. Typically, they never return."