Prof Alice Roberts joins Rylan to investigate witch trials in Chelmsford. Plus: an exposé of the international dog-fighting trade. Here’s what to watch this evening Prof Alice Roberts joins Rylan to investigate witch trials in Chelmsford. Plus: an exposé of the international dog-fighting trade. Here’s what to watch this evening 9pm, Sky History Rylan Clark returns to his old Essex stomping ground of Chelmsford – which he calls “witchcraft ground zero” – for this three-part series in which he