Wormhole to Hell or Wormhole to Heaven

This sci-fi thriller is about medieval people who travel through a wormhole in 1200 A.D. and arrive in what they think is hell. In 2015 A.D., National Security Agency (NSA) scientist Daniel Preadon travels through the same wormhole and arrives in scientific heaven. What happens when these two meet? The medieval people's descendants are surprised to hear Dan's assertions that they are not in hell, and he is surprised to hear of their insistence that they are in hell. So what is the truth? As the medieval people's descendants gradually accept Dan's point of view, Dan discovers things that science can't explain -- at least not yet. Maybe this will change if he gets back to earth -- or will it?