The McCalls are a young, honeymooning couple who feel they have the whole world ahead of them. While on their first trip as husband and wife, Samantha and Zach find themselves awake one strange morning with no knowledge of the night before. Months later, she finds out that she is pregnant. While this seems like terrific news for the loving couple, everything quickly goes horrifically awry. Inexplicable, terrifying complications plague Samantha and the McCalls are beset by the constant feeling that somebody or something is spying upon them. Over the course of months, Samantha's mental and physical afflictions worsen and their unfathomable origins become more apparent.