Dark angel, is based on the extraordinary true story of the victorian poisoner mary ann cotton, played by downton abbey star joanne froggatt. We meet mary ann as a loving wife and mother, newly returned to her native north east of england. But faced with abject poverty and an ailing husband, we see how ruthlessly determined she is to pursue her desires and a better life... Mary ann is a very female serial killer, a poisoner whose methods leave no visible scars, allowing her tally of victims to mount unsuspected by a victorian society unable to conceive of a woman capable of such terrible crimes. Travelling around the north east, she insinuates herself into unsuspecting families, marrying and creating new families of her own before killing them, taking their money and moving on. Through adultery, bigamy, fraud and murder, mary ann betters herself socially and financially. But the more she kills, the greater the risk her crimes will finally be exposed... Running time 180 minutes region region 2 release date 14 nov. 2016