Psuddenly Psychic by Aurelia Skye

Trapped with your high school class 25 years later—the textbook definition of Hell.
When three friends attend their high school reunion, they have varying expectations for the evening. Surrounded by the people they knew years ago—some who have changed, and some who definitely haven’t—is just as much fun as it sounds. They’re about to head out early when a bright light encompasses the school. Chaos ensues as a Hell gate opens in the middle of the gymnasium, and powers they never knew they had come to life.