Action-packed with adventure, the summer holidays for Emma and Grace mean travelling back in time using Gran's magic crystals. But this year they can't wait for it all to be over. Mum is still getting to grips with being a ghost and Olga has disappeared. It's believed she is lost in ancient Egypt. Once again the girls must take a trip through the ancient doorway to where a new and dangerous quest awaits them. Join Emma, Grace and their friends in the fourth book of this epic tale of mystery and suspense that takes themes from some of the greatest legends of the world.