The BBC continuity person doled out lots of warnings – sexual violence, physical violence and all the rest – before this three-part drama (stripped over three nights) started. There was no doubt – if there ever was any doubt – that this was going to be a harrowing, difficult watch. It was the story – another drama based on real-life events – of three girls who had been groomed and horrifically exploited by a paedophile gang (mostly containing, the story goes, Pakistani men, a fact that wasn’t lost during the reporting of the case by the British media when it broke in 2012). Nope, this wasn’t going to be a helter-skelter, fun procedural. It was going to be a very, very difficult watch.