Lesser Nefertiti

Why does the freshly excavated Egyptian tomb have a second, sealed door? And why has it been desecrated, and the mummy’s head severed?
As Clary illustrates the recovered artefacts, she forges a deepening connection with a young girl who’d become pharaoh when the wolf-headed Anup was being worshipped.
Can they stop the rites that will lead to the birth of the very first werewolf?