The Professionals - Season 1 - Eps 1: Private Madness, Public Danger
Charles Nesbitt, an expert on chemical weapons, threatens to contaminate the water sources of London with a lethal hallucogenic drug and in order to back up his claims, plans several small 'demonstrations' in warning to the local authorities - including CI5.
About The Professionals

Title: The Professionals
First Air Date: 1977-12-30
Last Air Date: 1983-02-06
Status: Ended
Rating: 7.4/10 (from 42 votes)
Language: EN
Seasons: 5
Total Episodes: 57
Network: ITV1
Genres: Action & Adventure, Crime, Drama
Production Companies: LWT
Synopsis
The lives of Bodie and Doyle, top agents for Britain's CI5 (Criminal Intelligence 5), and their controller, George Cowley. The mandate of CI5 was to fight terrorism and similar high-profile crimes. Cowley, a hard ex-MI5 operative, hand-picked each of his men. Bodie is a cynical ex-SAS paratrooper and mercenary whose nature ran to controlled violence, while his partner, Doyle, comes to CI5 from the regular police force, and is more of an open minded liberal. Their relationship is often contentious, but they are the top men in their field, and the ones to whom Cowley always assigned to the toughest cases.
Cast

Lewis Collins
Bodie

Martin Shaw
Doyle

Gordon Jackson
George Cowley