Complex sentence: The subject of this episode is of a young man living in a group just after World War Three; when he tries to leave, he is forced by the elders to stay and marry the only young woman in the group.
Split into simpler sentences: The subject of this episode is of a young man living in a group just after World War Three. When he tries to leave, he is forced by the elders to stay and marry the only young woman in the group.