The novel follows Sarah, a high-powered HR exec in an international consulting firm, as she experiences and is treated for a traumatic brain injury following a car accident. The type of damage is called hemispatial neglect (or "left neglect" in this case, since it's her left side). Essentially, she loses the experience of her left side. She's not paralyzed...she just cannot "see" anything to the left. It's rather hard to describe, but Genova (who has a PhD in neuroscience) does a fabulous job of illustrating not only the physical and mental issues associated with this injury, but the effect it has on Sarah's family and lifestyle. I highly recommend this novel.