The Devouring Hour

After a minor car accident, Kayla is forced to spend the night in a rural hospital room with a peculiar patient in the bed next to her. An elderly woman. She seems to be in a sort-of catatonic state and strapped down in the bed, yet it feels like her eyes are staring into Kayla's soul.
As the night goes on, Kayla starts to notice strange symbols etched into the walls and the woman's restraints begin to loosen ever so slightly.
Suddenly Kayla hears a whisper. Quiet, yet so loud at the same time.

"The Devouring Hour is coming."

As the clock strikes midnight, the hospital is plunged into darkness and Kayla comes to the realization that she is trapped inside with something ancient and malevolent.