I'm about 530 pages into this book I've been working on for way too long now. I'm getting close to a pretty monumental part of the story and following that is going to be the super awesome epic finale. So the problem is, I kind of... just got an idea for another story completely unrelated to the one I'm working on now. So on one hand, I really want to write something new because I've been working on this book for so long now. On the other, I've been working on this book for so long now and I don't want it to take any longer than it already is, or for it to get buried if I get invested in writing something else. I guess right there, that's one pro and two cons for writing something new, but do those hold the same weight? I'm not sure. The book I'm currently working on is a high fantasy setting and more on the darker side, while the one I'm considering working on might be somewhere between high and low fantasy (I don't know yet since I literally just got the idea for this yesterday) and more lighthearted, probably. The current one is oriented more towards action/adventure with some mystery elements thrown in, while the one I'm considering is sort of the reverse; mystery-focused with a little action/adventure thrown in. While the current one I'm writing is turning out to be very lengthy, as in beginning to look like it will be over 700 pages on completion, the one I'm considering will probably be shorter, but have more books in the series in the long run. So, thoughts? Opinions? I'll probably hold onto this idea regardless, but should I start it now or wait until the current book is finished? Edit: Another way to describe them might be that the one I'm working on currently is sort of like my Lord of the Rings, while this other series I'm considering working on would sort of be like my Harry Potter.