There are arguments as to what is the more important aspect of the successful horror tale or even a complete novel. Certainly character is essential as well as a strong plot, but it would seem that, without the suspension of disbelief, the story must fail. When H.P. Lovecraft addressed this argument in the 1930s, it was his opinion that atmosphere was the chief ingredient of the true horror story. I agree with that, and would add that verisimilitude is essential to the creation of atmosphere. There is much more to explore in this vein.