The Secrets of the Crystal Gem (Paperback) (ISBN-13: 9780646714189)

After their small victory in the Kingdom of Kudzu, Nikolai must now lead his group of friends to find the hidden Gem, rumored to be the Prince of Darkness's weakness.

The group journey to the Cave of Lumina, where the Gem is being protected by a mythical race thought to be extinct.

Riddles and monsters lurking deep within the cave separate the group, as they struggle to find the Gem and their way out.

Can the group find the Crystal Gem, each other, and a way out before the Prince of Darkness declares war?

Or will the Prince of Darkness and his creatures succeed in taking over the kingdoms, and soon the world.