Spenser: For Hire - Season 1 - Eps 15: Brother to Dragons
Spenser is going skiing with Susan, but when he picks her up at Smithfield High School where she works, he finds out one of her students died of a heroin overdose. Spenser gets hired by the superintendent and goes undercover as a teacher at her school to find out where the drugs are coming from. He obviously gets into it with the dealers.
About Spenser: For Hire

Title: Spenser: For Hire
First Air Date: 1985-09-20
Last Air Date: 1988-05-07
Status: Ended
Rating: 6.7/10 (from 30 votes)
Language: EN
Seasons: 4
Total Episodes: 65
Network: ABC
Genres: Drama, Crime, Mystery
Production Companies: Unknown
Synopsis
Mystery and suspense series based on Robert Parker's "Spenser" novels. Spenser, a private investigator living in Boston, gets involved in a new murder mystery each episode.
Cast

Robert Urich
Spenser

Avery Brooks
Hawk

Barbara Stock
Susan Silverman

Ron McLarty
Frank Belson