Based on true events from the producers of Dark Ages. 72 hours before the largest sea invasion in history, everything is ready, except for the weather conditions on the Normandy coast. The chief meteorologist of Great Britain, James Stagg, is called in to make the most important forecast in history, on which the fate of World War II will depend. Any delay creates the risk that German intelligence will notice the preparations, and the price of a mistake is the failure of the largest amphibious operation and defeat in the war. The final decision remains with the Supreme Allied Commander, Dwight D. Eisenhower. Just hours before the landing of soldiers under the command of General Montgomery, the fate of the war and the lives of millions of people hang in the balance...