When a delivery boy finds a severed head with the hair ripped off inside a newspaper stand, Catherine, Nick and Det. Sam Vega assume the case. In the autopsy, Dr. Robbins pull out a snake from her mouth and finds the serial number of her bridgework. The victim is identified as Veronica Juarez, and the investigators find a diploma from a university on the wall. They believe she is a gangbanger and they see a poster of the band Extremo. Nick and Det. Vega visit the club where Extremo is playing and they identify the victim as Carla. Soon they learn that the song that Extremo is playing is a ten-year-old narcocorrido that describes the way Veronica was murdered. Meanwhile, Greg, Sofia, Warrick and Capt. Brass investigate the murder of a man wearing and expensive suit shot in the head in the driver's seat of a handicap van. They identify the victim as Vincent Decarlo and they find that the victim was shot from a wheelchair. Soon they learn that the wheelchair belongs to Bonnie Bakerset, who lives in a nursing home, and a nice salesman has sold many things to Bonnie that has just died.