Al Perez, Chief of the U.S. Customs and Border Protection in Texas, fights to maintain his objectivity with the enforcement of his duties after his daughter, Adele, was brutally attacked by two migrants. However, he is forced to put his indifference aside when he receives a call about the mysterious death of a migrant at one of the detention centers that showed no sign of struggle. Slowly, more unexplained migrant deaths occur, raising more questions and no answers.
Unsure of how to solve this mystery, Perez reaches out to the FBI and gets in contact with Special Agent Bo McGinley, who begins to help investigate as the body bags begin to pile up. With the help of an FBI agent, Perez hopes these investigations will begin to move forward, but he is quickly proved wrong when sniper shots begin to fire from the U.S. border, rapidly killing migrants and cartel members.
With tensions rising, Perez and McGinley find themselves working under immense pressure, dealing with the constant demand for answers on both the mysterious deaths and the identity of the shooter. Each day, the list of suspects grows, and no one, not even Perez, is off the list. Will they be able to determine the cause of these mysterious deaths and find the shooters before an international and humanitarian crisis ensues?
