Mr. Howard, an Englishman vacationing in the South of France in 1940, is horrified when he learns of the evacuation of Dunkirk and the possibliity of Hitler invading England. Deciding that his place is at home, Howard makes plans to leave immediately for Paris and from there go to London. Despite Howard's dislike of children, fellow Englishman Cavanaugh, a League of Nations official, and his wife persuade him to escort their children, Ronnie and Sheila, back to England while they return to Switzerland. On the way to Paris, Howard and his charges stop in Joigny, where their train is commandered by the French military. When they board a bus to Chartres, Howard realizes that he has acquired a new ward, Rose, a French girl whose father works in London. Although Howard is angry at Ronnie, for whom he has a particular dislike, for inviting Rose to join them, he allows her to remain. Once again the travelers are disrupted, first when their bus breaks down and then when it is attacked by German aircraft. Howard soon realizes that he has a fourth child in tow: Pierre, a shell-shocked French lad whose parents were killed in the aerial assault. The final addition to the group is Willem, a Dutch boy, and Howard is mystified by the children's ability to understand each other despite their different languages. Howard takes his charges to the home of the Rougerons, whom he had met on a previous vacation. The Rougeron's daughter Nicole agrees to accompany Howard and the children to the seaside, in the hope of convincing her uncle Aristide to ferry them across the Channel. On the train ride there, Howard learns that Nicole and his son John, an R.A.F. pilot who was shot down two months earlier, were in love, and they comfort each other with their memories of him. After they reach a small village near Brest, Aristide arranges for a fisherman named Focquet to transport them across the Channel. As they are boarding the boat, however, the group is captured by German soldiers. They are taken to Major Diessen, a Gestapo officer, who refuses to believe Howard's story, suspecting instead that he is the spy who arranged for the English bombardment of Brest during a visit by Hitler. When Howard offers to confess to whatever charges Diessen wants as long as Nicole, Focquet and the children are released, the major is intrigued. Diessen learns from Howard that he intended to send the youngsters to his daughter in America for safekeeping and that he does not care that Pierre is Jewish. When Howard asserts that he would do the same for a German child, Diessen agrees to allow the group to go free if Howard will send his young niece Anna, who is half-Jewish, to his brother in New York. Howard agrees, and after bidding farewell to Nicole, takes the children to England. Soon after, Howard is in his London club, where he assures his friends that he did not have too much difficulty returning from France.