After being fired for taking an uncharacteristic risk at her commodities trading job, Bea Macon sublets her New York apartment and books a one-way ticket to stay with her mother, Christy, a free spirit who has been living in Salt Lake City on Bea's dime. Usually the responsible one, Bea isn't about to admit exactly why she's suddenly decided to visit, but she isn't the only one keeping secrets: Christy has a man. She has a map. She has . . . a username on a forum devoted to unearthing $1 million in buried treasure that an antiquities dealer claims to have hidden somewhere in the western U.S.? Bea is convinced this is just another one of her mother's wild larks, an elaborate way to refuse, as she has for Bea's entire life, to finally grow up. But Christy believes she's onto something--and she's arranged a rendezvous in a rural town called Mercy with the guy she's been obsessively trading theories with online to prove it. Out in the desert that one woman believes to be a promised land, the other a wasteland, they find themselves barreling toward a more high-stakes, transformative escapade than either of them could have imagined.