Somewhere in Germany after the war. A convoy of starving, lost children of all nationalities from the ruins of Europe or found in concentration camps is taken care of by employees of the United Nations. Among the children afraid of the UNRRA-uniforms is the little Czech Karel Malik who says nothing but one German sentence: "I don`t know". Obviously his family has been killed in Auschwitz. When they are to be taken to another camp, the scared children smell the exhausts of the ambulance, break up the door and escape to the ruins of the city. Later Karel`s cap is found floating on the river and he is falsely believed to have drowned. After wandering around for some time Karel meets the American soldier Steve, who has only a few more months to serve before returning to the States. Steve eventually convinces Karel to accept some food but the boy still remains silent. Steve talks Karel into returing home with him. Slowly he wins the boy´s confidence and affection. In the meantime Mrs Malik travel through Germany looking for her boy. From the UNRRA she receives Karel`s cap. Shocked she decides to stay in the camp for displaced people to care take care of children. Steve gives Karel new clothes, renames him Jim and teaches him english. He has decided to take the boy with him to America after he received an official letter confirming that all the boy`s relatives have been killed. While he is waiting for the immigration papers he leaves the boy in the same DP-camp that Mrs Malik has just left. She return to the camp only because she met another children transport. The people of the UNCCR have identified the boy and mother and son finally fall into each other`s arms.