In Spidersilk the novel, the story takes place in many different dimensions. There’s a lot of theories based on dimensions in our own dimension, which makes the story even more fascinating. In our world, we seem to stick to our layer of the dimension, but in Spidersilk Mark not only dominates on his own dimension but battles foes from another dimension and still travels via hyperspace through other dimensions, including the dimension in which he dreams.

For more information on multi-dimensions, check out this list:

http://www.livescience.com/46040-do-we-live-in-a-multiverse.html