That's because the Royal Oak Series is about spiritual evil and the incredible challenge of warring against it. The powers and principalities who rule the air entice people to use obscene language and to do obscene things. This is difficult subject matter for Christians, but it needs to be dealt with honestly if we are to understand its true nature.

So be warned: The Royal Oak Series contains the sort of language, violence and graphic descriptions that would easily earn it an R-rating if it was a series of movies (which it should be, by the way).

Dan realized, by making the decision to write in this way, that he was shutting off his access to the Christian publishing industry. He decided the honesty of his content was more important, and he trusts you, the reader, to see it the same way.