Longford, Channel 4’s big drama about Myra Hindley, the ‘Moors Murderess’, and the man who campaigned for her parole, got such a brilliant write up that I decided to watch.

It’s not a chirpy way to spend 90 minutes, but it was engrossing and thought-provoking. And controversial – where exactly were our sympathies being drawn? I know very little about the murders – born a generation later, to me it’s just two evil people who were locked up. But here I had my eyes opened to just why there was so much stir back in the day.

The real strength of the piece isn’t just the compelling subject matter, though, it’s the strong performances. Jim Broadbent pulls off a slightly loopy, deeply compassionate Lord Longford, suggesting the man wasn’t just nutty (I believe the long-standing impression) but a kind-hearted man pouring his energies into doing what he genuinely felt was right. The fact that two psychopaths lied to him and mislead him utterly shows him to be more than a little naive – especially when it takes years for him to consider a key piece of evidence.

Longford is obviously the focus, but Samantha Morton is brilliant as Hindley – somehow managing to make this reviled figure sympathetic, and then all the more chilling when the reality is revealed. And Andy Serkis (aka Gollum!) is absolutely chilling as Ian Brady, albeit resigned to a bit part.

Well worth a watch. It’s not comfortable viewing, not fluffly entertainment by any stretch, but it does raise questions about fighting for what you believe is right, and what does that mean when you were actually wrong?