Opal is certain of one thing: her missing mother is still alive. And when she learns the truth about her mother’s final expedition, Opal is ready to risk everything to bring her home. Join Opal, Gem, and Pyrite as they set off on an epic rescue mission―and this time, Marble is in on the adventure! Will they avoid the clutches of the Skarn warriors? Or will they be captured, never to return to Gemstone Village again? And wait a second―where is Obsidian? Shouldn’t he be with them? Find out in Hidden Gems: The Jewel of Skarn Island. The second book in the Hidden Gems series!