In part three, in a shocking turn, Erin Patterson takes the stand and brings doubt to every element of the prosecution's case. A ferociously capable witness, she withstands an onslaught of questioning over eight gruelling days – but does the jury believe her?

Part two tracks Erin's substantive efforts to conceal the truth, the explosive allegations surrounding her attempted poisoning of ex-husband Simon Patterson, her incriminating conduct in the days following the lunch and her continued lack of empathy for her victims.