The Calendar siblings, Lori, Joseph, Ahmed, and Elizabeth, famous archaeologists and members of the Greyhound Club, are truly… wild children: they don’t believe what they are told unless they see it with their own eyes, they love puzzles and mysteries, they persist in difficult times, and they do not hesitate in the face of danger.

When their parents are called to study the famous Papyrus of Hunefer, which is located in the British Museum in London, they have no idea they will experience an incredible adventure chasing down art thieves!

However, only the Greyhounds will notice a suspicious couple approaching, with ill intentions, towards the precious Ark of Anubis, which is exhibited in the same room as the papyrus… The pursuit of the thieves will take them from one end of London to the other and will awaken an unexpected interest in opera!