Jewel Mystery:Battle with the Devil - Jewel Mystery Series, #1

Laila meets the mysterious Gabrielle Nielsen in Paris, and together with the Man in Black she investigates these events and discovers a legend about a demon. In order to stop the mysterious organisation from awakening the demon, they discover more clues and engage in a fierce battle with the mysterious organisation. During the battle, they succeed in stopping the ritual of the mysterious organisation, but the demon still awakens.
In order to seal the demon, they start searching for a mysterious gemstone and eventually find it in a museum. However, they also face a robbery by the mysterious organisation and a fierce battle is inevitable.