Stratford Johns and Frank Windsor reprise their iconic roles as nasty and nice cops DCS Charlie Barlow and DCI John Watt. Charlie Barlow defined the nation's very notion of a no-nonsense, sharp-tongued police chief not averse to thrashing suspects into submission, while Windsor's Watt played mellower mind games with the villains. Together with their Special Operations squad, they tackle fictional Thamesford's most monstrous crimes and puzzling cases. Unafraid to address problematic social issues of the day, the series, like its predecessors 'Z-Cars' and 'Softly Softly', provided a startling window on police methods and the simmering tensions and resentments on the streets of 1970s Britain. Created by BBC crime stalwart Elwyn Jones, other popular returning characters include fellow 'Softly Softly' stalwart DS Harry Hawkins (Norman Bowler), dog handler PC Snow (Terence Rigby), cheery Sergeant Evans (David Lloyd Meredith) and troubled Chief Constable Cullen (Walter Gotell). Following the edgy tradition set by the earlier shows, most of these episodes were originally broadcast live.