I don't agree with one of the reviewers who compared this film to the American International Pictures. Basil Deardon has directed a brutally realistic film with an honest attempt to portray the rise of juvenile delinquency in post war England (but without the sentimentality of "Blackboard Jungle"). The cinematography was excellent as it really captured the scariness and isolation of the huge housing estate. The estate looked like an old prison. Stanley Baker was excellent as the hardened detective, reassigned to the juvenile division - "Urgent, urgent - Larceny - five iced lollies"!!!! He finds he is the butt of many jokes. David McCallum showed that he was one of Britain's top young talents of the fifties. (He had a very different role in another Stanley Baker film "Hell Drivers"). His portrayal of Johnny and the fanatical following he inspired was very frightening. Ann Heywood was also very good as the cynical Cathie. I wouldn't say there was a romantic subplot in it.
Detective Jack Truman is investigating a string of arson attacks by someone labeled the "Firefly". Just as he finds evidence which could lead to a breakthrough, he is assigned to the Juvenile Division - he is pretty disgusted at what he feels is not proper police work. Amid all the heckling he gets his first call out - the 6 year old Murphy twins are working a scam at the local lolly shops!!!
Taking the twins home he meets their brother, the charismatic Johnny, and their embittered sister Cathie. He starts to appreciate how life on the ghastly housing estates can turn young kids into criminals. As he gets more involved with the family, he realises there is a strong link between the fires, Johnny and a frightened Chinese youth who works for a laundry. The local priest (Peter Cushing in an unusual role, away from the Hammer horrors) explains that when Johnny was younger he had rescued some people from a burning building and had been hailed a hero. He wanted to recapture the feeling of importance and being useful and felt he could by lighting fires. The school siege was filmed in a very real way and the viewer felt the children's fear - the teacher (thinking only of her own safety) runs off and locks them in the room with the frightened gunman!!!!
I thought it was a really excellent film that tried to show some of the social problems Britain experienced after the war.
Highly Recommended.

Whatever his name is (the writer and director) should be locked away in hopes garbage like this is never made again. This one is in a battle with some of the most awful movies of all time. Sometimes movies are bad in a way that they're actually sort of good. Not this one. This was so bad I got angry. Seriously. A drunken 10 year old could have come up with a better script. What a waste. ALL the actors were completely uninspired to work at all, the CGI was barely acceptable, the sequences of scenes were completely retarded and hurt the little bit of story there was, it's like he just decided, "I want this to happen and this to happen, but I don't care how we got there, just shoot it and put it in. Whatever, I'm going back to my trailer to pick my nose, if anyone calls for me, I'm not here." Shame on you whatever your name is. Shame on you.