beefbroccoli 's review for:

Just After Sunset by Stephen King

The standout of these stories is "N".  It's about a patient N who may be suffering from OCD and paranoia (as diagnosed by his psychiatrist) because he believes a circle of stones in Ackerman's Field contains a doorway between his reality and another reality in which dwells a monster named Chtun.  Chtun is most likely to break through when the viewer sees seven stones when there are actually eight stones, leading to an obsession with numbers: odd numbers are bad, prime numbers are worse, even numbers are safe, etc.