Da Vinci's Inquest - Season 1 Episode 5 -

Following a rash of fatal drug overdoses, Da Vinci learns that one of the dead addicts had an infant, who is missing. Manny, a police informer leads Leary, with new partner Angela Kosmo, to the woman's drug dealers. They arrest Todd and Sioux, and through them Larry discovers that the killer heroin came from a French-Canadian supplier who, along with his partner, was murdered, gang-execution style, just days previously.