Mimi is a mystery writer who travels the world with her husband, "Papa," and their grandchildren Christina, 10, and Grant, 7. In Pyramid, the four travelers arrive in Cairo and are immediately thrown into a sinister mystery involving gun-toting thieves and deadly threats. The children are pursued by would-be tomb robbers and help solve the mystery when they run straight into the arms of Papa and a policeman. In Colosseum, Christina finds a mysterious message in a newspaper and immediately notices men in black trench coats everywhere.
