Emma and Alex love to solve mysteries. They have a new case--the crown jewels have been stolen! The royal family is upset. The friends want to find out who did it.

The friends look into the case. They visit the palace to look for hints and to talk to people. The workers of the palace tell them what they have seen.

Emma suggests watching the camera. They see a shadow sneak in and go to where the jewels are.

As they keep digging, they find more clues. They find a piece of torn fabric and a strange note. The note has symbols they think will solve the mystery.

The friends meet an old librarian who knows the symbols. She tells them the symbols are from an ancient secret group called “The Enigma”. The librarian says the group steals valuable things.

Emma and Alex set a trap with fake royal jewels to catch the thief. The thief takes the bait and gets caught. The group gives the jewels back to the royal family. The king and queen are delighted and thankful.