In the weeks before the 1979 Mexican elections, San Diego P.I. Alvaro Hickey follows the stories Baja California campesinos are spreading about visits from the Holy Virgin. Though Alvaro doubts her divinity, he's firmly on her side. She wants them to vote the corrupt and tyrannical Partido Revolucionario Institucional (PRI) out of power. When Lourdes Shuler asks him to unite her with her sister Lupe, Alvaro doesn't think much of it until Lourdes claims Lupe is the campesinos' Virgin. Alvaro's not the kind to turn down an appeal for help, especially from such a beauty. Besides, the published sketch a savant girl drew of the Virgin looks just like Lourdes. He suspects that Lourdes might not have a sister after all. Then, on their way to dinner, Lourdes and Alvaro pick up a tail. Lourdes admits the man could've been sent by her brother Andres. But is Lourdes hiding something more? Alvaro chooses to stand with the lady although he knows she might become his last adventure. Then someone arrives to rid the land of this vagabond Virgin....