The Professor and the Madman is a 2019 biographical drama film directed by Farhad Safinia (under the pseudonym P. B. Shemran), from a screenplay by Safinia and Todd Komarnicki based on the 1998 book The Surgeon of Crowthorne (published in the United States as The Professor and the Madman) by Simon Winchester. It stars Mel Gibson, Sean Penn, Natalie Dormer, Eddie Marsan, Jennifer Ehle, Jeremy Irvine, David O'Hara, Ioan Gruffudd, Stephen Dillane, and Steve Coogan.

Plot

In 1872 London, retired United States Army surgeon William Chester Minor suffers from hallucinations in which he sees himself being persecuted by a soldier he had to brand for desertion. During one of these visions, he mistakenly chases and kills innocent stranger George Merritt: for this crime, he is deemed insane and sent to Broadmoor. Meanwhile, Professor James Murray is admitted by Oxford University Press to the commission responsible for drafting what will be the Oxford English Dictionary, an impressive dictionary capable of listing every term of the English language and explaining its etymology and variations of meaning, with literary citations to support. The work began twenty years earlier, but completing it is difficult given the amount of work and the speed with which the English language changes. Murray thus has the idea of launching an appeal to the English people: he asks anyone who wishes to send the commission a postcard bearing a word reference. This earns Murray the post of commission director.