She-Ra: Princess of Power
A mysterious and dark location that resided on the planet Etheria, it was stated that no being or thing had ever returned from the Valley of the Lost. In later years, Hordak constructed a device known as the Magna Beam Transporter which teleported objects hit by its beams into the Valley where they forever be disappeared. He intended to rid the Evil Horde of the problem caused by the Great Rebellion by transporting the entirety of the Whispering Woods into the Valley. His plan failed when He-Man and She-Ra destroyed the weapon.
However, the claim that nobody ever returned from the Valley appeared to be an exaggeration, when Madame Razz, Broom and Kowl travelled to the Valley via the Freezing Mountains to visit the Library of the Vallery of the Lost. In the Inner Library, an even more secluded section of the main library, they found the Nameless Glowing Book and managed to undo a spell Shadow Weaver had unleashed on She-Ra and other members of the Great Rebellion at Mystacor.
It can be concluded that Shadow Weaver had also visited the Library in the Valley of the Lost before the three couragous hearts, to find the same book. Weaver most likely used a teleporting spell to get in and out of the Inner Library without the Librarian noticing it.
In the shooting script for She-Ra Unchained by Bob Forward, the Valley of the Lost is discribed as "an odd, ominous-looking mountain formation somewhere in the Etherian version of Siberia. A circular range of steep-sided peaks completely surrounds a fog-shrouded interior."
- The Secret of the Sword
- She-Ra Unchained
- Three Courageous Hearts
- Enemy with My Face (mentioned)
- Birds of a Feather
- The Rock People