Anna is afflicted with severe agoraphobia, and her crippling fear of the outside world confines her to the safety of her home. When three men break in and invade her house on the outskirts of town, she is physically unable to flee, frozen by her phobia. But the intruders soon discover that looks can be deceiving. Within her home, Anna is hardly helpless at all… harbouring dark secrets and a deadly will to survive.