Sim and his mum never live anywhere long. When dangerous strangers appear one night, Sim finds out why. His mum has been keeping secrets: she has the power to open doors in time. Running for their lives, Sim and his friends are determined to outwit the sinister Council of Keys and be the first to find Nefertiti's lost tomb and a powerful door to Ancient Egypt. They must piece together long-hidden clues if they are to solve the mystery of her golden heart scarab. Can they find it before the Council finds them?