Richard Powers would be my favorite writer if only he wouldn't stray into fantasy/sci fi. Luckily for me, The Echo Maker is firmly set in the current day, and, even though the main character doesn't know it, the world is as normal as it gets.
Obtuse enough? Probably more than enough, so I'll get to it.
The book opens with a 30ish woman being called to her childhood home to care for her brother, who has been in a horrific accident. He gets better faster than anyone expects, but his brain isn't wired the way it used to be.
He develops a fairly rare disorder known as Capgras Syndrome, in which the people closest to you seem like strangers. He sees that his sister looks just like his sister, but his amygdala has been damaged and he's lost his emotional attachment to her. So his brain tries to explain this by assuming she's someone who has been sent to spy on him or keep track of him--for reasons he can't figure out.
Clearly, his sister is devastated by this development. Their parents are dead, and she's always taken care of him through his troubled youth and adulthood. She knows she'll have to shoulder the burden alone, and she's determined to hang in and face whatever comes.
One of the most frustrating things for her is that he's very antagonistic to her, but he's desperate to see his sister. He thinks someone has kept his sister from visiting him, and this breaks her heart. One very small benefit is that she sees how much she means to him, but, as I said, that's a very small benefit.
Powers writes about the scientific and medical issues behind this syndrome so seamlessly. His skills are extraordinary. The story carries you along, and you barely notice that you've learned so much about the brain, and how it's organized.
Supporting characters include the neuropsychiatrist who's in charge of the case, and a former boyfriend who lends a much needed hand.
The book is a powerful reminder of how fragile our brains are, and how we rely on those closest to us. It's a beautiful portrait of family and duty and determination. I recommend it highly.