In the crucible of war, one man struggles with his duty to his country and love.

Gene Sinclair's life's goal was to become a medical doctor, to get away from the tedium of teaching high school chemistry. But as World War II looms, Sinclair is drafted and sent to train on coastal artillery. Sinclair sees his life's plan ruined by the army and struggles to find his place. Eventually when he is posted to the pharmacy training program, life in the army seemed to be improving until Pearl Harbor attack.

Dragged back into the artillery, Sinclair is sent to the ninety-day Officer's Training School. Despite his resolve to avoid romantic relationships, Sinclair meets Sarah Gale and falls in love with her. Commissioned as an antiaircraft artillery officer, Sinclair struggles to come to grips with his duty as an officer and to Sarah Gale as she joins the WAACs.

The war separates the young lovers when Sinclair's unit is shipped to Australia. There they continue training to fight the Japanese and adapt to the challenges of jungle warfare. Then, sent for specialized training in Darwin, Sinclair experiences the harsh reality of the war during a Japanese air raid on the city.