User blog comment:Misakichii/Which Demigod will lead the 7 to the Doors of Death?/@comment-4507215-20111107233528

Thanatos said in order to find the doors of death you need to be able to see the signs to lead you there the only demigod known to be associated with death is Nico, or a child of Hades/Pluto, so it could be Hazel as she has been through the doors of death before and may remember their location