Pretty to see, hard to catch. That's how girls like Mac always are- they've grown up quicker than their peers, they know who they are and what they want and where they're going. They don't have time for drama or relationships or long nights out drinking. They like what they like, and what Mac likes is geology. Petrology, specifically. The study of rocks. And it's this love that sends her on a trip to Yosemite in search of a small, hidden cave hikers claimed to have found diamonds in. But there are those in the forest that see a pretty girl like Mac and want to pin her down, forever.