Grendel

After suffering a near-fatal heart attack, CEO Tyler Leto finds his sleep plagued with identical nightmares, his psyche tortured in a dark world that he's convinced is Hell. Every night, Tyler dreams. Every night, he's surrounded by darkness. Every night, a mysterious figure haunts his dreams. The figure will not relieve Tyler of his nightmares until Tyler performs one very important task. But in order to complete the task. Tyler must relinquish what remains of his immortal soul. He must decide, and he must do it quickly. Because every morning, Tyler wakes up more exhausted than the day before. Every morning, Tyler is closer to death. Called "an impressive piece of literature" by Bookpleasures, and "fast paced" by Hellnotes, this is one story you'll surely want to dive into.