After a child in a day-care center dies of a virus, Briscoe and Curtis try to find the source of the infection, leading to a case involving an extramarital affair, embezzlement and a drug manufacturer.
After the detectives find a murdered postman and a woman who was left for dead in her apartment, the investigation leads to a serial killer and a surprise.
The murder of a corrections officer leads detectives to a women's prison where a guard was linked to an inmate Carmichael put away on drug charges and a confrontation with defense attorney Danielle Melnick.
The double murder of a wealthy man and his daughter leads the detectives to the wife and stepmother of the deceased. However, Canada's objection to the death penalty hampers McCoy and Carmichael in seeking crucial evidence for obtaining a conviction.
When Briscoe and Curtis discover that a high-level federal official found murdered was recently transferred from Baltimore, they re-team with Baltimore homicide detectives. The joint investigation reveals that the victim was involved in an affair with a high-level government official whose career will be destroyed if it becomes public. The independent counsel summons McCoy and Ed Danvers to Washington to demand McCoy reveal his source or be jailed for contempt.
This crossover continues on Homicide: Life on the Street S07E15 Sideshow (II).
After a teen is found dead in the emergency room, the investigation leads to a case involving a religious ritual and a defendant who claims that the action taken was dictated by a saint's voice.
The investigation into the shooting of a newspaper columnist leads to a murder case from two decades earlier and involves a suspect who at that time had been a juvenile.
After a philosophy professor is pushed in front of a subway and killed, the investigation leads to a suspect who, following a divorce, changed his identity and disappeared with his daughters.
The death of a corporate mogul caused by an overdose of a sexual performance-enhancing drug leads to a case with a witness that puts Curtis in a compromising position.
A coed's killing leads to a case involving the deceased's relationship with a professor and two male students who vouch for each other's whereabouts on the night of the murder.
A shootout between a motorist and the police leads to the discovery of a gruesome Russian mob killing --- and a traumatized boy who was an eyewitness to the murder.
McCoy and Carmichael risk violating the civil liberties of witnesses when they are forced to jail them in order to safely continue their investigation.
