Julian Fellowes Investigates: A Most Mysterious Murder is a British five-part docudrama series produced by Touchpaper Television, which premièred on BBC One on 16 October 2004.
1929. Three members of a respectable middle-class family, all living along the same street, die one after the other. The first two deaths are incompetently put down to "natural causes" by the local quack. But the third starts to cause a scandal. Exhumations reveal arsenical poisoning in all three. Who among the remaining members or close associates was the murderer?