Just as Mannion and his ex-wife, Sherry, are making plans to get back together, their son, Jack Jr., arrives for a visit. He brings his new girlfriend with him and they announce they're taking a year off college to travel through Europe. The problems grow bigger when Jack Jr. is confronted by his dad for using ecstasy and is later arrested at a rave party for possession and traffic. Meanwhile, a kidnapped woman calls from a car's trunk begging for help before she is killed; Nick has to face neighborhood problems at his new house and Parras is confronted and suspended by her superiors after her gun is stolen by a man she picked up at a bar and used to kill a man.

Mannion has to handle an international crisis after the son of the Colombian ambassador is discovered to be the main dealer of the heaviest type of heroine yet. Threatened not to do anything about it, Mannion studies the international code for diplomatic immunity and plays around until he gets Eduardo kicked out of school and arrested. Meanwhile, Temple helps a heroin addicted woman; Ella has problems with Ricky after he returns from summer camp; Jack Jr. goes to court for his drug problem and Nancy finds Jack a new assistant.

A construction worker finds the skeleton of a dead boy. He was Noland's last case before promoted - a case that was never solved. Now Noland devotes all his efforts into putting an end to this crime. They finally arrest the boy's mother, who also killed another son of hers. Meanwhile, Mannion tries to change the child abuse scenario in the city. Nick negotiates a possible candidature of Mannion's for the upcoming mayor election. Ella has to fire an old employee but manages to keep him. Parras has trouble dealing with an abusive father that reminds her of her own father, until it is proven that such father never touched his problematic 14 year-old son.

Mannion investigates the murder of two young women, one of whom is identified as Debreno's sometime girlfriend, Maria.