In Spidersilk the novel, multiverses play a huge role in the story. The main character Mark hails from another dimension as do the intruders that attack Mark’s friends. Theories about multiverse have been around for quite some time, but they are changing often. More recently, a theory was published that there is a parallel universe that runs time backwards. Fascinating? Check out the theory here: http://www.iflscience.com/physics/there-parallel-universe-thats-moving-backwards-time