What is the theme for the novel the warriors?

The theme? I don't really think it has a theme. It is the book where Lionblaze, Hollyleaf and Jayfeather dicover Squirelflight isn't there mother and Brambleclaw not their father. Its also the book where mysteriously Ashfur is murdered by Hollyleaf. the theme though? Whoever asked this question message me. We can chat about it.