Cruising features director William Friedkin diving deeper into the dark recesses of man, with this unique approach to the serial killer thriller one that is both frustrating and engrossing, and led by a haunting Al Pacino.

There is no doubt that Friedkin (The French Connection) is at his best when he explores the extremes of the human condition. Because of this, his films can often be disturbing and thrilling with equal measure, made even more so by the reality-based approach that he utilises.

Cruising isn’t Friedkin’s best movie, but it is certainly his most intriguing. Based on the book by Gerald Walker, the film tells the story of police officer Steve Burns (Al Pacino) who goes undercover in the underground gay leather S&M scene as he hunts a serial killer preying on gay men.

Although straight, Burns takes on the case with assurances he will make detective. Taking on a new alias, he frequents the varied S&M clubs across the city where he gets the lay of the land and learns the rules needed to navigate it. Many moments can indeed be shocking, with Friedkin never flinching from portraying what he claims to have seen during research for the film. Actual S&M clubs in New York City’s meat packing district were used in the film.

It all works in presenting territory alien to both the viewer and Pacino’s character, who flounders from bar to bar, club to club, and slowly becomes immersed in this world of leather and kink, in which a killer prowls for his next victim. Movies featuring undercover cops often deal with themes of loyalty and identity. Cruising takes a step further and deals with sexual identity, with more than subtle hints into Burns’ struggle with his own sexuality. Pacino plays this with the right amount of ambiguity, naivety, and haunting complexity.

Cruising of course is a serial killer movie, yet so immersive and shocking is its deep dive into its unique environment that the crime element certainly feels rather second fiddle. The scenes of murder are indeed shocking in its violence, and there is a perplexing mystery as to who the killer is (Friedkin revels in the ambiguity), yet this cop-gone-leather thriller just does not get the balance right to make it one of Friedkin’s best, although it is better than what its sordid reputation suggests.