The Trail of Serpent’s Tears is a portal network established by Keoth Amsetis, also known as the godking Set of Mulhorand and the god Sseth of Serpentes. Keoth Amsetis discovered many pre-existing portals and linked them to portals of his own making as he travelled towards the Jungles of Chult following the footsteps of the sarrukh (and using many of their ancient portals). Keoth later used many of these portals to flit between Serpentes and Mulhorand as desired.
Its existence was first discovered in 881 DR: Year of the Brazen Vizier by an ambitious priest of Set called Aap Nura. Aap Nura had thoroughly researched Set’s mortal life and was certain he had a secret hideaway somewhere in the Sunset Mountains, and after several years of searching he located a cave now known among the followers of Set as Thebarahnas (the Serpent’s Palace).
It wasn’t until 400 years later that the current incarnation Seti discovered a portal beneath the Tower of Set, that he realised the true purpose of the Serpent’s Palace and the existence of the Trail of Serpent’s Tears.
The Trail of Serpent’s Tears has many overlaps with the World Serpent’s Undulation, including the Library of Mdaess
The Serpent’s Palace: The Serpent’s Palace is a deep well excavated into a mountainside about 30 miles south of Daggertooth Pass. The well is marked only by a sigil; that of a coiled cobra, which was the sign of the House of Amsetis and Set’s personal symbol. Beneath the cover-stone, the well descends over 200 feet into total darkness, with only shallow grooves carved into the side of the well.
The chambers at the bottom of the well is surprisingly well furnished with cushioned chairs of ornate design, a well stocked bookshelf of Mulhorandi literature from 3000 years ago, and an extensive laboratory for magical experimentation. In the sleeping quarters Aap Nura discovered the a collection of scrolls from the Book of the Serpent, and a vial of Set’s blood.
At the far end of the library is what resembles an unfinished doorway that ends in the solid rock of the mountain. This doorway contains the portal to a hidden chamber beneath the Thaymount, but the portal will only open for whomever carries the blood of Set; specifically the vial found in the bedroom, and holds the Alabaster Staff.
Seti rediscovered the Serpent’s Palace around a decade ago after he found the portal beneath the Tower of Set and realized the purpose of Set’s hidden caches. After having cultists retrieve Anraset’s bone marrow from the bottom of the Gbor Nor, Seti travelled through to the Thaymount and discovered more of Set’s treasures and another portal leading to the Darkcrypt, which in turn contained a portal leading to the Tower of Set.
The recovered pages of the Book of the Serpent, as well as some of Set’s personal effects have become sacred treasures of the Cult of Set, while Seti himself has kept the rest of the Trail of Serpent’s Tears secret from his cultists while he attempts to discover the rest of the network and what ultimately happened to Set.
The Library of Mdaess: This secret chamber is apparently completely inaccessible except through the use of the portal located in the Serpent’s Palace. How Set managed to reach this ancient repository is unknown but it is possible the portal located here has another destination (requiring a different key).
The library is made up of a series of smoothly sculpted, stone chambers, each in a dome shape. Lining the walls are sealed pots containing a honeycomb like mesh, each infused with a variety of different taste markers at different points along the mesh. In the centre of the largest chamber is a circular depression lined with reptilian scales the size of a human hand, along with millennia of dust and other debris. Hidden beneath the dust is the long decomposed (3000 years old) corpse of a humanoid reptilian creature with a long snakelike tail instead of legs.
This chamber was once a vast repository for the Ba’etith, the stone pots contain a collection of the stored magical works of Okoth but using a taste language that only a snake-like creature could understand. Seti was unable to divine the purpose of the jars and has left them unmolested, but he did discover a portal hidden just above the sleeping area (the bowl like depression), which required a piece of the fabled Orcgates in order to activate (the original Orcgate was broken apart by the Mulhorandi and was later used by the Red Wizards in their experiments, however few realize that the Orcgate had a twin located elsewhere).
The Darkcrypt: This shrine was constructed upon the orders of Horus in the immediate aftermath of Ra’s death (or so the secret historical records in Mulhorand recount). Inside the shrine was placed the Staff of Ra (also known as the Ankh of Life), and the Darkcrypt was sealed and its location forgotten.
The Darkcrypt was later rediscovered by retreating soldiers in 922 DR, the incarnation Ramanthanhur volunteered to be resealed within it to protect it from being plundered by the Red Wizards. Ramanthanhur however has not discovered the location of the portal Set established within that leads to the Tower of Set in the Raurin Desert.
The Alternate Forgotten Realms 