Now, as I said, there are many different ways to write a parallel universe. My best advice to you is to be consistent. But in case you're having trouble deciding how the gears turn in your parallel world, let me give you a few concrete examples:
1) I'll start with Christine Warren's Others series. In her books, there are three worlds: Earth with shifters, vampires, and the like; an Underworld with demons, imps, etc.; and Faerie, consisting of (you guessed it) fairies. Here, alongside Earth, we have a world of light and a world of dark, although the occupants are not necessarily kind- or evil-hearted. In essence, you have an echo of the classic Heaven-Earth-Hell scenario.
You can introduce the same in your own piece of writing very easily. In order for this type of parallel world to be convincing, you need to have some sort of reason for there to be a light and a dark world. The easiest would be to base your story off some sort of religion, and incorporate an actual Heaven and Hell. I'll let your own imagination roam free for the details of this land, but if you're writing an angel-demon story (whether or not some creatures, like vampires for instance, might be thought of as "demonic"), this is an ideal way to base your worlds. If you think of Hell as either dark or torturous, developing your world will be a lot easier to do.
2) Next, I'm going to draw on Angela Knight's Mageverse series. This is a prime example of a magic world. Here, there are two worlds, one which is the normal Earth, free of all magic, and another which is a magical world. In the magical world, magic runs free, and this is where witches and magical creatures stem, and where they can use all forms of magic the best.
If you use this type of parallel world, I caution you: make sure you set down rules for how your magical system behaves. Magic cannot simply run rampant or your world will be unbelievable. Does it work through runes? A certain language? Artefacts? Do you need a sacrifice? Or is the cost of the magic taken out on the wielder himself? I once read it brilliantly worked in the Obsidian Mountain Trilogy by Mercedes Lackey and James Mallory, where for each piece of magic performed, they were given a task to complete. This task could be anything, but the magnitude of the task depended on the magnitude of the spell performed.
Something else to keep in mind if you decide to write this sort of parallel world is how the magic will affect Earth, or be affected by Earth. Will your spellcasters be able to work it on Earth? If so, will it take a more taxing toll? One thing to remember is that rules are there for a reason, not to be broken. Think of physics. Because of gravity, I can't fly (howevermuch I'd like to). In order for your world(s) to come alive on the page, you must set the same sorts of limitations on the magical existence.
Lastly for this type of parallel world, think of what magic would do to the world itself. You have to assume it won't be identical to Earth. Perhaps there are fluxuations in the magic, which cause magical storms, anomalies, or deformed creatures.
3) My third example is best shown in MaryJanice Davidson's Canis Royal series. Unlike the other two, this is a magical world which cannot be crossed into often, and it can only be crossed into by dying on Earth. Because the crossing is absolute, this is a world which is completely set apart from Earth. This type of parallel world is a good choice for those seeking to highlight their fantasy world with comparisons to our world and society.
4) Although I have yet to read a romance novel that employs this sort of parallel world, the fourth method I can think of is to have a parallel world which echoes our world. For instance, every action in this world has an equal and opposite reaction in that world. One good thing would illicit one bad thing, one birth would bring one death, and so on. Of course, there are other ways for two parallel worlds to be linked, but that is the one which immediately comes to mind.
Whichever type of parallel world you create, you need to also think of a means of getting there. You could:
- Cross worlds with a feat of magic.
- Cross worlds only at certain times of day, month, or year.
- Cross worlds only at certain places.
- Cross worlds only upon death
- Never have your characters cross worlds. Instead, create two main characters, one in each universe, and feature them in your story. This is especially effective in the case of the two worlds being linked.
Good luck with your writing! Next week I'll talk a little about marketing before I launch into a mini-series about mythological creatures in late May or early June.