The Black Phantom

When Vika finds a rare black phantom crystal while caving she's not the only one who feels its pull. The school bullies kidnap her little brother and demand the Black Phantom as ransom. Vika and her fraternal twin are lured into a mine and stumble on a sinister and unearthly industry beneath the ground. Trapped, separated from her brothers and facing unimaginable evil, Vika realises she will not escape the chamber of horrors without losing plenty that is precious to her. Her own life is the very least of what's at stake. What little hope she has rests on her getting the Phantom back. The question is, how much fear can she take and still keep fighting, for the sake of the place and the people she loves?