No, you really don't. You just have to be modestly creative. Fiction is full of allusions and references and expies of older works' characters and settings.

No, you really don't. You just have to be modestly creative. Fiction is full of allusions and references and expies of older works' characters and settings. Rather a few stories have been written as answers or counter-arguments to other works without having to use the same names or be explicitly set in the same setting.