Rachel Childs is a journalist working for a news channel in Boston. Her father left when she was very young, and her indifferent mother will not disclose his identity causing a dysfunctional relationship. After her mother's untimely death, Rachel cannot find clues to her heritage, leaving Rachel feeling lost and alone. She hires Brian Delacroix, an alleged PI to find her birth father, yet does not learn much.

On assignment in Haiti after the devastating tsunami, Rachel falls apart, having a breakdown on the air from the horrors she witnesses. Her boss, believing she is drunk fires her immediately, and her marriage to her colleague is over. She is aimless and suffers severe anxiety becoming housebound. The author describes her panic very visually:

"It started with a tickle in the center of her chest. The tickle quickly became a piston. Her mouth would turn Saharan. The piston would transform into the sparrow, imprisoned and panicked. It would flap its wings---whomp, whomp, whomp, whomp--in the hollowed out core of her, and sweat would sluice down the sides of her neck and pop on her forehead. Breathing would feel like a luxury with an expiration date."

Rachel, though mainly a prisoner in her own home encounters Brian again. They become close then marry, and he helps her alleviate her symptoms of agoraphobia. Then Rachel going by gut feelings learns Brian is not who she thinks he is. She begins to stalk him bringing her on a whirlwind escapade and putting her life in danger.

Since We Fell is, in essence, three stories: Rachel's question of her paternity, her mental decline, and her lack of trust. This novel is an intense and gripping, white-knuckle psychological thriller filled with emotional conflict and a nail-biter plot that doesn't end.