Claire McGowan, What You Did

I got this as an Amazon First Reads selection, and I'm glad I did. It kept me interested and guessing to the end. Six friends from college get together for a reunion—two couples, Ali and Mike and Jodi and Callum, and two singles, Karen and Bill. They spend the night drinking and reliving their Oxford days, and everything is great until Karen staggers in from the backyard claiming she was raped by Mike. It's he said/she said, and Mike's wife, Ali, has to choose sides. Things get worse from there. At the same time, there's a ghost in their past: An acquaintance was murdered at the very end of their time at Oxford, and her attacker was never found. Could there be a connection? Anyway, it's a book worth reading.