A grizzled U.S. general leads his men against the Japanese in Burma during World War II.

In 1944, Brig. Gen. Frank Merrill's 5307th Composite Unit, known as Merrill's Marauders, is deep behind Japanese lines in the dense Burma jungle. Even though the 3,000 men suffer from exhaustion, illness, and starvation, they are ordered to capture a gun emplacement, an enemy arsenal, and a railway yard. Merrill realizes that his men cannot be an effective fighting force without rest, but he also knows that they must make the 500-mile trek to Myitkyina to prevent Japanese and German armies from merging in India. Following an enemy raid, however, the Marauders are virtually walking dead men, physically and mentally incapable of launching a new attack, and Merrill himself collapses from a heart seizure. He arises from the stretcher, however, and urges the men to keep moving. They watch in silence as he staggers among them and falls unconscious, until Lieut. Lee Stockton, inspired by Merrill's indomitable spirit, rallies the men for one last campaign and drives them forward. When Merrill regains consciousness, fresh troops and supplies are landing on the Myitkyina airfield, which has been liberated by the Marauders.