The Lynch Mob by Steve Wyffels

A compilation of the books: "The Placebo Effect" and "The Nocebo Effect"

*Adam gathers his friends around the fire to tell a story: Seth has an unfortunate accident which leaves him struggling to distinguish his nightmares from reality... and as time goes on, things only seem to get worse.
*His sister Arielle makes a sinister discovery in the house their family recently moved into. She tries to control the evil but fails.
*Seth's mentally ill mind mixed with Arielle's evil antics brings a storm of terror to the Lynch house, a storm which there is no remedy for.
*Adam says it's just a story, but only moments after the story has ended do his friends realize there is something seriously wrong...