I hadn't heard of this series previously but realizing the quality of the cast decided to watch.Soon I was hooked and waited for each episode eagerly.
The scripts seem realistic and plausible.
The villains have an air of menace and realism.
This is old fashioned policing with none of the modern no comment and solicitors present.
Tommy Butler the famous London detective apparently had some input and it shows.
Shot in monochrome it has a period feel and I don't understand how I had missed it completely when it was first broadcast.