"Darkest Hour" -- ★ ★ ★

Gary Oldman's transformative portrayal of Winston Churchill in Joe Wright's historical drama "Darkest Hour" achieves the same rarefied orbit as Marlon Brando's interpretation of the Godfather. If this be critical blasphemy, so be it.

Oldman lacks the real Churchill's bulldog eyes, but he captures the obsessive drive and pit bull spirit of the prime minister who promised Great Britain nothing but "blood, toil, tears and sweat" as he waged all-out war against the advancing Nazis.

Churchill may be the main character, but the true subject is the atomic-bomb-grade force generated by fusing rhetoric with conviction.

This calculated, unabashedly audience-pleasing drama treats Churchill the way many biopics profile great artists.

It illustrates how Churchill created his verbal masterpieces, constantly revising his texts right up to the moment he addresses Parliament or speaks into a radio microphone. It celebrates the craftsmanship Churchill employed to produce stirring, inspirational messages under great pressure and tight deadlines.

It pays glorious tribute to the power of words in scenes where the prime minister's often terrified new secretary, Elizabeth (Lily James), operates her typewriter like a machine gun, hammering ink into sheets of paper, producing sentences packing the power to give a frightened nation strength and hope in the face of unspeakable evil.

Winston Churchill (Gary Oldman) shares a tender moment with his wife, Clementine (Kristin Scott Thomas), in "Darkest Hour." Courtesy of Focus Features

The smart, taut screenplay -- by "The Theory of Everything" writer Anthony McCarten -- covers a crucial month in 1940 when Churchill assumes government leadership while dealing with undermining political adversaries, plus cautiously courting support from a highly skeptical King George VI (Ben Mendelsohn).

McCarten cleverly aligns our sympathies with Oldman's grumpy old man by treating him as an underdog.

Nobody likes the self-righteous prig. People associate him with the disastrous Gallipoli fiasco in World War I.

Everyone around Churchill seems to be a nervous Nellie, anxious to strike a peace deal with Hitler before his marauding forces sweep through France and come knocking on London's door.

Churchill's first major speech vowing "We shall fight!" alarms most of Parliament, especially ineffectual former Prime Minister Neville Chamberlain (Ronald Pickup) and his Snape-ish ally Viscount Halifax (Stephen Dillane). King George shares their concerns that the alcohol-fueled Churchill will seal the fate of the commonwealth, not save it.

Winston Churchill (Gary Oldman), left, meets with King George VI (Ben Mendelsohn) in "Darkest Hour." Courtesy of Focus Features

Then, the impossible rescue of 300,000 British soldiers at Dunkirk shifts perceptions. (For that story, see Christopher Nolan's "Dunkirk." Wright's movie doesn't show us the actual chess pieces of war, but the thought that goes into moving them.)

Wright, who directed the splendid wartime drama "Atonement" (I've seen it four times), wisely allows Churchill to suffer periodic doubts about his abilities and plans.

His wife, Clementine (Kristin Scott Thomas in a truncated role), flushes out his human side as a family man, although it's obvious that the prime minister never took the time to raise his own children.

In "Darkest Hour," Churchill frequently quotes Cicero, but his real literary muse should be William Shakespeare, specifically the Bard's "Julius Caesar" in which Marc Antony turns a hostile audience into a massive ally through the use of words.

Churchill accomplishes the same feat with his own speech punctuated with such passion and conviction that it turns Wright's "Darkest Hour" into Oldman's finest.

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Starring: Gary Oldman, Kristin Scott Thomas, Lily James, Stephen Dillane, Ronald Pickup, Ben Mendelsohn, Hannah Steele

Directed by: Joe Wright

Other: A Focus Features release. Rated PG-13 for thematic elements. At Chicago's River East and Century Centre, plus the Evanston Century and the Regal Lincolnshire. 125 minutes