Unemployed professional geologist and sometime FBI consultant, Em Hansen desperately needs work. So when her best friend Faye tells her that she knows someone who could use Em's expertise as a geologist to authenticate a painting, she jumps at the prospect. The painting is by the famous painter of the American West, Frederic Remington, and Em's client has had it in his family for years. But he believes it's a fake and wants Em to use her forensic skills to analyze the pigments to prove it. Since pigments are just ground-up minerals, it's a perfect task for a geologist like Em.
Although Em doesn't quite trust Faye's friend, she sets aside her doubts and takes the case. Following the painting's trail takes her from Wyoming to Utah to Washington, D.C., and Pennsylvania, and then it takes an unexpected sinister twist, putting Em on the trail of a murderer too. Suddenly she's the only one who can find out what's going on in time to save several lives, including her own.