And She Was, by Alison Gaylin

Gaylin makes you work for it, but she delivers a very fine book -- multi-layered, complex, and well-imagined.  In particular, she gives you a sense of what it might be like to have Hyperthymestic Syndrome, the ability to remember every detail of every moment of one's life, and to live with someone for whom the past is more compelling than the here and now.  The main character, Brenna Spector, has that ability. She is a private investigator (and mother) who is hired to locate a missing woman. With help from that freakish memory, a tormented police detective, and her talented and annoying assistant, she discovers links between the woman and a missing child case from some years ago.  In 2013, I'll be reading the next Brenna Spector book, but until then I might just check out some of her other works.