This won't be the best movie you see this year, technically speaking, but, with the Trump administration complaining about "fake news" and boasting about "alternate facts," it still might be the most important movie you see. That's because it deals with denialism, the rejection of empirical and verifiable evidence that is otherwise uncontested and well supported by a critical consensus. There are many forms of denialism in our culture. Many Christians deny our best science about evolution and the age of the earth. ExxonMobil contributed to pseudo-scientific groups that claim that the science of climate change is inconclusive. There are deniers of the moon landing, vaccinations, and the safety of genetically modified foods. This historical drama by director Mick Jackson brings to life the story of the Emory University historian Deborah Lipstadt and her book History on Trial: My Day in Court with a Holocaust Denier (2005), about how she was sued for libel by the Holocaust denier David Irving. The lesson here is clear and disturbing, that we should take very seriously even the most outlandish incidences of denialism.