I have recently seen many authors who have been said to be plagiarized off of. Please, please, please realize that this is a serious offense that cannot go overlooked. If you draw inspiration from someone or something, ask for permission to use that piece of work as inspiration. If they do not give you permission, back off. Don't pursue it further. If they do give you permission, change it. Don't copy lines word for word. Give credit where it's due if some chapters are more influenced by something than others. Don't even phrase it similarly. Be creative. Don't change just a single work and claim that is completely different from what you drew it from. To use a metaphor, the author just gave you permission to use the materials to build the house, not the entire groundplan of the house.