Undergo by Amanda Russo:
 
In the summer of 1999, Ally and her friends dared to explore the hotel's hidden depths, venturing into a place that should never have been disturbed. The once majestic hotel, now a decaying ruin, harbors a sinister history that left them forever scarred.
 
Behind a mysterious wooden door lies the chilling truth of that night—ghostly apparitions, violent entities, and psychological horrors that twisted their reality. Each encounter blurred the lines between the living and the dead, sanity and madness.
 
Every year, Ally is irresistibly drawn back to the hotel, compelled to confront the shadows of her past. As she retraces her steps through the desolate halls, she unearths buried memories and faces the malevolent forces that still linger. Her journey is a desperate quest for answers, but each revelation threatens to pull her deeper into the abyss.