Militant union agitators are in the firing line. Sir James Darren has a major building work in progress. The unions are for it.
Holroyd (Ray Smith) is a political troublemaker who runs things by mob rule. He is already bullying a local cafe owner for not letting Holroyd sell his pamphlets and raffle tickets.
David Main has been hired to look for a way to being down Holroyd's intimidation tactics.
It gets serious when Walter Clegg is beaten up by Holroyd and his cronies. Holroyd finds out that Clegg is ex police, he also warns Clegg that he knows where his grandchildren live so he better keep quiet.
The unacceptable face of trade union activism is examined. The 1970s were notorious with some trade union leaders who cared more about their egos than their union members.
Maybe the way Main brings Holroyd down is just too neat and simple. I did like the twist that someone else was running Holroyd all the time.
I couldn't help noticing that Stuart Wilson who played a junior solicitor for Main in an earlier series, turns up as a different character.