It seems to me that the Otherness exists, certainly as a "seperate" storyline, independent of Jack, there is no question of that. However as I stated earlier it seems to me that Jack's life and his life's work has been moved and molded to be a part of the "war" raging between the forces of the Otherness and the somewhat less threatening and possibly merely indifferent "good side" represented by the women with dogs, and the other characters throughout FPW's books which have appeared, and fought that Otherness. I certainly wouldn't be opposed to seeing more stories about Jack tackling fix-its which have no supernatural element to them, because it can't always be about the Otherness ( sometimes a cigar is just a cigar, thus people need stuff done, and Jack can do the fixing, no Otherness or supernatural). But my main point was that in the storyline of Jack and the Otherness it seems as though Jack and his work is somewhat a result of supernatural action, in that the supposed "good side" seems to have been moving him into a position to work for it as it sees fit, and having him in the "fix-it" role is quite handy, since he has access to information and firepower, etc... He also seems to be moving up the chain of command of the forces of the Otherness and thus becoming more visible to it at the same time, it stands to reason that the Otherness would be interfering more in his life as time goes on and their plans are thwarted or delayed, no?
In answer to a post on this thread about where Jack had his first encounter or "push" towards this supernatural element I have the following comments to contribute. It seems to me that it must have been at least since the death of his mother as it seems "forces" are diligently working to make Jack alone, as his family is killed one by one etc... However since much of what follows in these stories is about destiny and cosmic design it must therefore follow that Jack has had a connection with and a role in the "battle" since birth, or conception, and one has to wonder if Jack's mother had a dog? What were the circumstances of his birth? We don't know the answers to any of these questions but it is possible to take a guess. Based on my reading I would have to say Jack had an unusual birth, his childhood had more than a "normal" share of weirdness (possibly encounters with ghosts, paranormal, etc...), the death of his mother was a catalyst, possibly designed and implemented by the "good side" possibly not. I also feel that his mother and father both knew a lot more about all of this stuff than they ever told Jack or let on to anyone that they knew.