The Intruder is a psychological thriller by #1 New York Times, USA Today, and Wall Street Journal bestselling author Freida McFadden, published October 7, 2025 by Poisoned Pen Press. This 279-page hardcover was a Goodreads Choice Award nominee for Readers' Favorite Mystery & Thriller in 2025, and has earned over 341,000 ratings on Goodreads with a 3.89-star average.

When a ferocious hurricane traps Casey alone in her remote wilderness cabin, she discovers something far more terrifying than the storm: a young girl lurking outside her kitchen window, covered in blood and clutching a knife. The girl won't say where she came from, and when Casey makes a disturbing discovery in the middle of the night, it becomes clear the stranger harbors a dark secret she'll kill to protect. In this taut tale of survival and desperation, McFadden weaves dual timelines — present-day terror and a heartbreaking past — into a propulsive story about how far someone will go to save themselves.

Freida McFadden is a practicing physician specializing in brain injury who lives with her family in a centuries-old home overlooking the ocean. She is renowned for her bingeable, twist-filled psychological thrillers.