The Sweeney there were two spin-off movies. Sweeney! was the first and was released in 1977.
Detective Inspector Jack Regan (John Thaw) and Detective Sergeant George Carter (Dennis Waterman) are hardcase coppers with Scotland Yard’s elite Flying Squad. This time they’re involved in an unusual case involving the potential for international intrigue. This is the sort of thing that would normally be dealt with by Special Branch but the script gets around this difficulty by having Regan get involved in an indirect way, doing a favour for a particularly useful informant named Ronnie Brent.
Ronnie’s girlfriend has just died. A verdict of suicide was brought in at the inquest but Ronnie is adamant that Janice would never have killed herself. He asks Regan to look into the case in an informal sort of way.
The case proves to involve corruption at the highest levels, with high-class call girls used as bait, and organised by people to whom mass murder is just routine stuff, just another day at the office.
Ranald Graham’s screenplay is in fact a little overblown. One gets the impression that this movie is trying to be a conspiracy theory political thriller of the sort that enjoyed some popularity in the 70s. It’s not the kind of story one associates with The Sweeney and Im not sure it was a terribly good idea. It’s the kind of story that needs a very big-budget approach. It also has a slightly transatlantic flavour to it which is odd since one of the reasons for The Sweeney’s success was its thoroughly British feel.
This may be the reason for the political thriller plot - if the film was going to end up looking like an extended episode of the TV series then the grandiose plot would provide the necessary cinematic feel.
Sweeney! also takes advantage of the opportunity offered in a movie to increase the level of violence and the level of bad language and to add some entirely gratuitous nudity. This actually turns out not to be an advantage after all - it makes the movie seem a bit too much like just another generic action thriller.
It’s not that this is a bad movie. It’s just that fans of the television series are likely to be disappointed that it bears very little resemblance thematically or stylistically to the series, which is a problem since one assumes that the target audience for the movie would have been, primarily, fans of the TV series. Sweeney! is a 70s paranoia thriller. If you like that sort of thing it’s OK but pretty routine and the plot is rather silly at times.
Sweeney! is definitely a bit of a misfire.