18.98: An ONC 2023 Thriller

It's referred to by several names: the ghost frequency, the haunted frequency, the fear infrasound.
You can't hear sound at 18.98 hertz, but your body feels it, and when it does, some believe you've opened yourself to the world of the supernatural.
Liv used to believe the ghost frequency was real, and so did her friend, Helina. While Liv came to shun this notion, Helina went in the opposite direction, becoming obsessed with using the ghost frequency to access a paranormal plane of existence. Now, Helina has gone missing, and her brother, Graham is convinced the ghost frequency has something to do with it... and Liv is the only one who can find her.
Liv agrees to help Graham search for his sister, but she brings with her memories of a fraught relationship and a great and unforgiveable harm done-a harm so deeply scarring, she's willing to do something terrible to gain revenge, even if it means losing Helina, and even herself, forever.