After WWII, Berlin lies in ruins. For Gustav, Willi and their friends the rubble provides an adventurous, dangerous playground. Especially for Gustav, it helps pass the time, as he longs for his father's return from a POW camp. One day a stranger arrives, looking helpless and hopeless.

Alex St. George, a young RFC pilot, is anxious about fighting in the First World War. He is comforted by sensitive shop assistant Kitty, and the two fall in love, marrying before Alex is sent to the front. But his snobbish mother disapproves of the match, and when Alex returns home paralysed and in a cataleptic state, Mrs. St. George plots to keep him from his wife until she can arrange an annulment. But the determined Kitty has plans of her own....