In 1941, when more bombers are needed for the Allied war effort, workers from all over the country flock to the Lockheed Aircraft plant in Burbank, California. Among them is Corky Jones, who plans to stay with his old college friend, Brad Maple. Corky has a low draft number and intends to avoid the draft by obtaining a job in the defense industry. Brad is delighted to see Corky again, but his wife Roma is not happy about an additional mouth to feed. Brad, who does not have a job, has spent their savings on a correspondence course in aircraft engineering, only to discover that the school is a fake. The next day, Corky undergoes an extensive security check at Lockheed and soon obtains a job in the storeroom. With an advance against his salary, he buys several bags of groceries as his contribution to the household. Roma is delighted with the food, but Brad is so jealous that Corky moves out. Corky rents a room from German immigrant Jake Hanso, a supervisor at the plant, and his son Pete, Corky's co-worker, who plans to join the air corps upon his graduation from college. Later, Roma leaves Brad and gets a job in the personnel department of the plant. Pleased that she is free, Corky immediately asks her out to dinner. Things grow complicated, however, when Brad also finds employment at the plant. Eventually, the two men come to blows over Roma. At work, Jake asks the workers to donate their services to build an extra bomber, which they will then give to the English soldiers as a Christmas present. Later, Jake is fired because, although loyal to the United States, as an enemy alien, he is not allowed to work in the defense industry. Pete is angered by his father's treatment and abandons his plans to join the air corps. Although saddened by the event, Jake admits that his dismissal is his own fault, as he waited too long to apply for citizenship. Together with Corky, he helps Pete realize that he still wants to fly bombers. Jake then finds work in a diner until his citizenship application is completed. After several months, Pete completes his education and joins the air corps, and Jake becomes a citizen. Father and son vow that one will make the bombers that the other will fly--Hanso to Hanso. Afterward, at home, Corky and the Hansos hear that the Japanese have bombed Pearl Harbor. Pete returns to the base, and Corky and Jake hurry to the plant, where production is stepped up. After the Japanese attack Corky changes his mind about evading the draft. He reunites Roma and Brad and joins the air corps. Then, after Pete is killed in the Philippines, Corky promises Jake that he will down two Japanese bombers in Pete's honor, and does.