The Darkest Hour follows Winston Churchill (Gary Oldman) in his first, and arguably most treacherous, month as Prime Minister of a nation engulfed in the perils of World War II. The film begins with the ousting of Neville Chamberlain, a misguided politician more concerned with the well-being of his nation than the fate of all of Europe.

Following Chamberlain’s resignation as Prime Minister, the Conservative Party sets forth Winston Churchill, a resilient, strong leader with a tricky accent and a proclivity for cigars and daytime drinking.

The remainder of the film follows Churchill through May of 1940, a month filled with uncertainty in England as Parliament is split on whether to pursue peace talks with Germany or dedicate all resources to victory in Europe over fascism. In addition to the partisan battles, Churchill must handle the 300,000 British soldiers trapped by German forces in the town of Dunkirk, France.

While the film is through the eyes of Churchill, an array of historical figures also encapsulate the war-time effort. Clementine Churchill (Kristin Scott Thomas), Neville Chamberlain (Ronald Pickup), King George VI (Ben Mendelsohn) and Churchill’s typist Elizabeth Layton (Lily James) intensify the film’s feeling of the importance of the decisions Churchill is making.

While the 125 minute film sometimes feels drawn-out and static, Gary Oldman gives a brilliant, riveting performance as Churchill. Not only has Oldman undergone a complete physical transformation, but he takes on every single last mannerism of Churchill’s.