One of the main themes could be power. The gun often represents power in a story. It can give a character a sense of control or dominance over others. Another theme might be danger. Guns are inherently dangerous, and this could be explored through the events in the story, like the potential for harm or death. Also, it could touch on moral issues. For example, how the character who wields the gun decides to use it - whether for good or bad can raise questions about morality.
Well, in 'the gun short story', I think a theme is fear. The presence of a gun can instill fear in characters. They may be afraid of getting shot or of the person who has the gun. And then there's the theme of change. Maybe the introduction of the gun into the story changes the dynamics between characters. It could make some characters more assertive while others become more submissive. It's all about how the gun affects the relationships and the situation in the story.