“Darkest Hour” could easily have been a one-man show – with a transformative piece of work from Gary Oldman as Winston Churchill – and been a film that is well worth your time.

Fortunately, director Joe Wright doesn’t rest on the incredible work of his lead actor. The result is a crisply paced film with many layers, thanks to a supporting cast that brings depth to the story and Wright’s sharp eye behind the camera.

Make no mistake, Oldman is the story here as Churchill. He effectively captures Churchill’s boorish behavior that is both charming and frustrating. “Darkest Hour” begins with Churchill’s rise to prime minister right as Nazi Germany is rolling through Western Europe.

With British troops seemingly pinned in the harbor of Dunkirk, France, many of Churchill’s colleagues want him to negotiate a peace treaty. Churchill refuses to give in and stands his ground – determined to rally the nation and preserve a country he deeply loves.

Oldman should not only be a shoo-in for an Oscar nomination, he should be the slam dunk winner – a career-defining piece of work that only comes around every so often. He doesn’t just imitate Churchill, he inhabits the prime minister’s persona in such a manner that it becomes easy to forget who is underneath all the makeup.

But “Darkest Hour” has much more than Oldman going for it, with a strong supporting cast as well.

Kristen Scott Thomas is great as Churchill’s wife, Clemmie, the one person not afraid to go toe-to-toe with her husband and one of the few people who could rein him in.

Ben Mendelson is good as King George, while Lily James also is strong as Churchill’s secretary, Elizabeth Layton.

Wright allows all of those characters to get their moments to shine in “Darkest Hour” as well, zipping through this story in a manner that is much lighter than I expected. We get tight shots of the smoke-filled Parliament, with Wright bringing a visual flair that we have seen in his previous work “Hanna” (and even the much maligned “Pan”).

Wright’s direction along with Oldman’s Oscar-worthy work makes “Darkest Hour” a worthy addition to a trio of films about the events at Dunkirk (along with “Their Finest” and “Dunkirk”). “Darkest Hour” gets the unofficial trilogy going, setting up the next two films, while providing insight into why Churchill was ultimately the right man to be prime minister at the time.

Starring: Gary Oldman, Kristin Scott Thomas

Directed by: Joe Wright

Rating: PG-13 for some thematic material

Playing at: Regal Greenwood Mall Stadium 10 (Highland Cinemas)

Grade: A