Based on the best-selling novel by Simon Winchester and inspired by the true story of the individuals who attempted to write the first edition of the Oxford English Dictionary in 1857. Professor James Murray (Mel Gibson) quickly discovers the endlessness of the task. Recruiting members of the public to assist in the challenge, he receives invaluable help from Dr. W.C. Minor (Sean Penn) - a patient at a facility for the mentally ill. A captivating drama of madness, genius and obsession, Steve Coogan, Natalie Dormer, Eddie Marsan and Jennifer Ehle co-star.