After the fall of France during World War II, world weary newspaper correspondent John Davis and his pregnant wife Nora travel to London where they are met by John's colleague, Herbert V. Allison. Although John pleads with Nora to return home to the safety of Connecticut, she refuses to leave his side. As more European countries fall to the Germans, Nora fears that John has become jaded and is loosing his conviction. One night while on a foray into the blitzkrieged streets of London, John encounters a little boy clutching a stuffed lamb buried in the rubble left behind by the German bombers. Upon returning to his hotel, John discovers that Nora has been injured in the air raid and taken to the hospital. At the hospital, the doctor informs John that Nora has lost their baby and will never be able to have another. Although the doctor has advised John to withhold the bad news from Nora, she senses the truth and is driven to hysterics. While trying to calm Nora, John finds the little boy's lamb stuffed in his coat pocket. Months later, Nora has recovered her health but not her equilibrium. She is about to fly home when Allison asks her to stay with John and face what has happened to her, but denying the extent of her pain, Nora disregards his advice and returns home. Assigned by Allison to write a story about an orphanage for war refugees, John proceeds to the Riswick Children's Home and meets its director, Trudy Strauss. There, John is moved by the traumatized children, the innocent victims of war, and recognizes the little boy he pulled from the ruins. Trudy explains that the boy, Peter, has not spoken since coming to the orphanage. When John returns the stuffed lamb to the boy, Peter develops a profound attachment to him and John promises to join him later for tea. Afterward, one of the foster parents returns to the orphanage a troubled little girl named Margaret. From Margaret's neck dangles a chain holding the casing from a bomb. When Margaret refuses to part with the bomb and continually wipes her dry eyes, Trudy coaxes her to shed her tears of mourning for her dead mother. At tea, Peter begins to come out of his depression and relate to the other children. Later, John helps bathe the children and Margaret and Peter both vie for his attention. After the children are put to bed, the rumbling bombers strike and John comforts the panicked Margaret. That night, the city is enveloped in flames following a bombing raid. As John and Allison prowl the streets in search of a story, John comes upon a woman carrying the lifeless body of her child. His anger aroused by the atrocities of war, John becomes revitalized and goes to see Margaret and Peter. There, Trudy tells John that the children are being sent to meet their prospective foster parents, the Barries, and asks John to take them to the Barrie house. Upon arriving at the house, the children cling to John. Although the kindly couple showers them with gifts, Peter and Margaret are morose and after Margaret begs John not to leave her, he takes them back to the orphanage. Deeply perturbed by the children's distress, John cables Nora that he is coming home and asks her permission to adopt the children. He receives a reply from Nora's mother, notifying him that Nora is ill but will undoubtedly want the children. Soon after, John receives a cable from Nora, relating that the notion of a real home with children shocked her back into reality and that she now will welcome the children into their family. When John tries to arrange passage for the children back to the U.S. however, he discovers that the plane for the first leg of the journey, from London to Portugal, is completely full. When he proposes asking one of the passengers to relinquish their baggage allowance so that both children can travel on the flight, Susan Fleming of the British Ministry of Information provides him with a list of the passengers. When all eight travelers either cannot or will not respond to his pleas, John is forced to leave behind one of the children and Trudy insists that an intelligence test should determine which lucky child will accompany him. After Margaret scores highest on the test, Peter, dejected, retreats into his shell. As John and Margaret board the train for the airport, Margaret, who at first is angry at John, breaks down in tears at the idea of leaving Peter behind and calls John "Daddy." At the airport, John and Margaret are walking toward the terminal when a car carrying Mrs. Bailey, one of the passengers, appears and Peter climbs out. The elderly Mrs. Bailey then explains that she has foresaken her baggage so that Peter can fly to Portugal and there board the ship bound for America and a new life. As their ship approaches New York, the children are thrilled by the glistening lights of the city. Nora tearfully greets her new family aboard the boat, and when the air raid sirens wail and the lights slowly blink out, Nora assures the children that they will go on once the war is over, never to be extinguished again.