The Intruder by Freida McFadden original

Casey's cabin in the wilderness is not built for a hurricane. Her roof shakes, the lights flicker, and the tree outside her front door sways ominously in the wind. But she's a lot more worried about the girl she discovers lurking outside her kitchen window.

She’s young. She’s alone. And she’s covered in blood.

The girl won't explain where she came from or loosen her grip on the knife in her right hand. And when Casey makes a disturbing discovery in the middle of the night, things take a turn for the worse.