The Yellow Balloon(1953)
One of two young boys accidentally falls to his death when playing in a bombed-out London neighborhood. Frankie, the survivor feels guilty about his friend's death. Len, a petty thief who has just killed a pub owner during a botched robbery, learns of the accident. He poses as Frankie's friend and blackmails the boy into stealing from his parents to finance Len's escape. When Len decides that Frankie may know enough to connect him with the murder, he decides to silence the boy in a tense "hide and seek" chase through the ruins.