For two years Ashley Colton (Abbie Cornish), a rough, ragged beauty in her mid-twenties, has walked a tightrope, trying to prove that she is fit to be a mother and regain custody of her son. A surprise visit from her father (Will Patton), a truck driver living in Mexico, brings Ashley back into a turbulent and unresolved relationship. On a trip to Nuevo Laredo, she discovers that her father is smuggling immigrants across the border. Ashley glimpses a solution to her problems and is lured by the prospect of easy money into the role of a coyote. Her improvised plan quickly goes awry, and Ashley finds herself stranded with a young girl whose mother disappeared in the late night river crossing. Along the way, she discovers something unexpected, something she didn't even know she had her own mothering instinct.