I'm working on an idea that takes place in the future and involves a transmittable mutation in humans. The most important aspect is that the mutants don't have blood. I'm thinking their bodies create and function on electrical energy instead. One of the main characters (but not the protag) is a scientist who transforms some people into mutant and back to human during the story. I'm more concerned about the story than the genre, but I guess this is soft sci-fi? The idea just came and took on a life of its own with a plot and characters that I think are good. It's only the science part giving me problems. I've spent the past few days learning more about blood and related things than I ever really cared to. I know this mutation is never going to be realistic, but I like to keep my ideas consistent and as realistic as possible within the premise. I feel it's important for me to understand, to some extent, how the mutation works, but I'm getting frustrated and don't know if I'm going overboard. I know plenty of stories boil down to, "It is this way because I say so." Even in real life I don't understand how everything in the body works. But I still worry it's going to sound ridiculous. How far can I stray from reality before it gets ridiculous? How much detail do I need to know about how the mutation works--just enough to keep consistency and know the outcomes on the body/characters/society? Should I not bother so much with why and how it works? How much needs to be explained to the readers? Does this all just depend on the story itself/the genre/the audience preference? Am I worrying too much?