A disturbing episode – it would seem so easy for somebody to do this. Indeed the story seems partly based on the alleged plot by the IRA's "Balcombe Street" active service unit to poison a London reservoir. However I still cannot understand why LWT insisted this be the opening story, when 'Old Dog with New Tricks' was clearly intended to be the pilot and is a better episode, anyway.

Nevertheless this segment has some fine moments and dialogue: the "Music Hall Act" scene, of course, the interrogation of Sutton is superbly acted by all three participants and the way Bodie handles the drug-racked Susan shows that even in these early stories he was a more complex character than people usually give him credit for.

The episode moves along at a splendid lick and the action scenes are well-choreographed but none of the support characters really captured my imagination. Perhaps if the episode had been written in a way that we could sympathise with Nesbitt and his ideals it would have provided an extra "dimension".

Favourite line: "What are you two? Some kind of Music Hall act?" / "Whatever we are, you made us!"

The ongoing theme (remember, this is supposed to be the second episode!) of competitiveness between B and D is shown in opening scene where they're shooting at targets. Here we also see the continuation of the bad "jokes" from Bodie and participation in the comedy angle from Doyle. The dialogue in this episode is more natural and Doyle has lost some of his "staginess". However, he does wear the Infamous Plaid Jacket for the first time, foreshadowing some serious wardrobe-challenged moments in later eps. Doyle is still driving here. Doyle also is acquiring interesting personal characteristics: e.g. the "sniff" he gives just before he decides to wait with Benny for the strip show to end before arresting Sutton. MS seems to be "getting" the character now (IMO Lew had Bodie from the start).

The plot is scary and possible. Nice use of an idealistic nutcase who actually wants to do harm. One false note: the "tasting" of Susan's heroin stash – c'mon, guys! Good technique with the two interrogations: Bodie of Susan and Cowley and Doyle of Sutton. One done with kindness and some mild emotional brutality and the other with near extreme brutality! Nice cuts back and forth here.

Bodie's character doesn't have a lot of development in this one, but Doyle's nasty side comes through loud and clear: first the scene where he fakes beating up Benny but definitely intimidates the real villians in the bar and second when he deals with Sutton. The way he says "CI5" and gives poor Sutton that Look... my, my! When Cowley is actually preparing (and I think he would have) to shoot up Sutton we can see Doyle's concern. He seems willing enough to go along, though. And at the end of the show when Nesbitt, defeated utterly and wounded, lies in the bottom of their boat for the ride back, Doyle shakes his fist at the man. Ray has a multi-faceted personality!

Twice B and D go counter to Cowley's direct orders - this in contrast to their unquestioned obedience in 'Old Dog with New Tricks'. As they move into action during the climax of the story we see real physical teamwork and get to see Doyle almost fly as he crosses the wooden bridge. MS was in marvellous shape!

Bodie manages to kid around during what was a potential disaster of tremendous proportions, and Doyle chides him.

But at the end they again walk off together!

On Nesbitt's arrival at the reservoir in the pre-titles, the camera pans past a sign announcing "World Chemical Products Sports and Social Club". THe sign misspells the word "secretary". (Well-spotted Jamie Davis!)

When Bodie and Doyle arrive at World Chemical Products, they meet some of the senior staff in Mr Harvey's office. Revealing that chief chemical analyst Mr Cummings would be able to test the vending machines for ADX, Harvey appears to pick up the telephone to talk to Cummings.... despite the fact he is stood in the very same office!?! (Thanks to "Nicolas")

Some time after this episode was repeated by ITV in 1979, a cut was made which has endured on subsequent UK TV transmissions (and the Video Gems issue). Just prior to the title sequence we see Nesbitt hand Susan some drugs. In uncut versions we then see Susan tightening her belt around her arm. Using Nesbitt's cigarette lighter to sterilise a needle, she then shoots up. The excision may have come about because of a tightening up of censorship rules by the Independant Broadcasting Authority (or Independant Television Committee as they are now known). Thankfully the missing segment is present on the Contender video and DVD issues and VCI's 1988 release. Very many thanks to DanaJeanne Norris and Ros Connors for info!

Keith Barron (Nesbitt) has been a well-known face on TV since the early 1970s, with myriad leading roles in various sitcoms (eg Duty Free, Haggard, The Good Guys) and one-off police dramas such as '1998' and Police 2020. Recently starred in the BBC's National Crime Squad: Manhunt mini-series.

Di Trevis (Susan) appeared in a great Sweeney episode, 'Bait' but appears to have dropped out of acting in the early 1980s.

Trevor Adams (Benny) was a regular in the 1970s sitcom The Fall and Rise of Reginald Perrin but quit acting in the 1990s and sadly passed away in 2000.

Penny Irving (Pam the, ahem, "exotic dancer") was a nurse to young Mr Grace in Are You Being Served? and starred in early seasons of the holiday camp sitcom Hi-De-Hi. Nothing since as far as I'm aware.

Christopher Ellison - in a small role here but later to appear in 'The Rack' - became a major player in ITV's long-running police drama The Bill as Detective Inspector Burnside. Also starred in the terrific 1986 children's drama Running Scared concerning small-time villains running inner-city protection rackets. More recently seen as a dodgy land developer in Martin Shaw's Judge John Deed series.