WMG / Mummy: The Curse

Duat and the Underworld are one and the same.

Duat is the place where Mummies go when they go into henet, Right? And they lose almost all their memories on the way either there or back. The deepest Dead Dominion, the Ocean of Fragments, destroys memory. Thus, I posit that the Rite of Return transports the Mummy's soul through the Ocean of Fragments, shielding it from some (but not all) effect of the Ocean, to Duat beneath. Whether the Judges are Kerberoi, Cthonics, or just insanely powerful Mortal Sorcerers is uncertain.