Lord Geoffrey Blackwood is the main antagonist of the 2009 film. He is a cultist and performs several human sacrifices before being brought to justice. He wishes to see Holmes in prison where he warns Holmes of three more deaths that will change the nation. He is then hanged and pronounced dead by Dr. Watson. The following night he supposedly bursts out of his tomb and runs across the cemetery, leaving the night guard catatonic. In the following week, three important figures are murdered as Holmes struggles to make sense of it all. He eventually discovers that Blackwood plans to kill the members of Parliament with a poisonous gas machine thus starting a civil war. Part of the machine is taken by Professor Moriarty while Holmes is distracted chasing Blackwood and Irene Adler to the unfinished Tower Bridge. Holmes and Blackwood then have a sword fight atop the bridge until Holmes pushes Blackwood off the bridge onto a mess of chains and ropes where he deduces the methods of the science behind Blackwood's trickery. Blackwood becomes entangled amongst the chains and falls catching his neck on a chain thus hanging himself.
Blackwood was played by Italian actor Mark Strong.
The idea of a cultist as a villain came from Sir Arthur Conan Doyle's fascination with the occult.
