Who is Dayani Cristal? is a mystery inquiry pursued on two levels. The film makers follow the Pima County sheriff's department and medical examiner's office as they first discover and then seek to identify the body of a young man found in the desert, 'only twenty minutes drive from the city of Tucson' - a search that involves eventually at least one foreign consulate. The other line of inquiry is into who this person might have been when they were alive, where they came from, what their aspirations were, and why they would leave home, risk riding the rails the length of Mexico and crossing the desert of northern Sonora. This second inquiry is accomplished by the film maker following the possible route of a migrant - and putting us into that person's shoes. As we follow the actor on his way north, we see from up close real people on the migrant path, finding hospitality in unexpected places, and sometimes losing their way. The two strands of the mystery come together at the end ...