With the US economy once again booming, Mexicans are crossing the U.S. border illegally in alarming numbers—at a time when terrorist acts are taking place at the boundary line. Protest marches in Phoenix over a "Stolen Southwest" only aggravate what has become an explosive situation. The C.I.A, tasked to investigate this escalating national security threat, recruits Professor Neal McGrath to help. McGrath, a former Special Forces officer who has worked previously with Langley, has valuable contacts in Mexico City. To add to the tension, the beautiful C.I.A operative, Elena Rodríguez, with whom McGrath shares a romantic and dangerous past, is assigned to work with him. Together they unearth a deadly international conspiracy that puts their lives in danger at every turn.