The Book of Gates
When
c. 1300 BCE onward, New Kingdom
Where it survives
Royal tombs, notably those of Horemheb, Seti I and Ramesses VI
What it is
A second, rival description of the sun's twelve hours of night, differing from the Amduat in scheme and in cast. Each hour is entered through a gate guarded by a serpent that must be named. It includes a striking scene showing four groups of humanity, Egyptians, Nubians, Asiatics and Libyans, all under the care of Horus.
Read it with this in mind
That two incompatible route maps of the same journey were carved in the same tombs is the point rather than a problem. Egyptians did not require their cosmologies to agree, and a modern reader looking for the correct version is asking a question the material does not answer.
Other sources