Alan Turing was a complex man, a mathematical genius who broke the seemingly unbreakable Enigma code through which the Nazis conducted their war on Europe with encrypted messages. Before that he was a highly gifted student at a public school, years marked by endless bullying and the awakening of homosexual tendencies. At a very young age, he becomes a Fellow at Cambridge University where he produces a number of remarkable papers. With the mental agility of a borderline autistic genius, he is a pioneer without whom computer science and artificial intelligence would not exist today.

At the beginning of WWII, he is hired at Bletchley Park, Buckinghamshire, where Britain’s code-breaking center was located. With his team, he manages to break the German code, thus shortening the war and saving countless lives. His life story, as sad as that of individuals too different not to be lonely, takes a tragic turn when his sexual “perversion” is disclosed some years after the war. In an age where homosexuals received long jail sentences, he accepts chemical castration instead but the potent medication has horrendous side effects and he commits suicide.

On the basis of this picture, Morten Tyldum, the Norwegian director of “The Imitation Game,” Turing’s life story based on Andrew Hodges’s biography, is neither a genius nor a complex man. Neither is Harvey Weinstein who distributes this biopic put together in time for the Oscars. It is conventional, predictable, with a soaring Alexandre Desplat score recycled from any number of similar flat biopics based on the real life of extraordinary people who, as recounted Hollywood style, become-yawn inducing repetitions of a hundred other movies.

The difference here is, of course, the mind-blowing performance by Benedict Cumberbatch as Alan Turing, insufferable and moving, arrogant and determined, a socially inept genius, the man without whom our lives today would be very different. The actor inhabits the main character thoroughly, yet with a subtlety that keeps him clear of caricature or exaggeration–truly a grandiose act, one for the books.

Given its subject matter and the riveting Cumberbatch ably assisted by his fellow actors, “The Imitation Game “ cannot help but be entertaining. But it heavily lurches from tensions between the team and their bureaucratic overseers to victory in breaking the Enigma code to the final indignities in Turing’s life–unthinkable today when gay rights, if not quite established, have hugely progressed. Hard not to compare this inert production to another recent film—no biopic that one—“The Man of the People” about Lech Walesa, the out-of-work Polish electrician who overthrew communism and became President.

But then, the director was Andrzej Wajda.