Detective Cassie Maddox is called in to investigate the murder of a girl who eerily resembles her–and who happens to be using the name that was once her undercover alias. Pretending that the victim was only in a coma, not dead, Cassie infiltrates the girl’s strange group of five best friends to find out what happened.
The Secret Place by Tana French
In order to solve the murder of a teenage boy, two detectives must investigate warring girl cliques at an exclusive private school.
John Dowell believes he has the perfect marriage and the perfect set of friends. Then he discovers that everything his friends and wife have told him is false, and his entire life is based on lies.
Special Topics in Calamity Physics by Marisha Pessl
Blue van Meer befriends a strange group of kids and their charismatic teacher at a fancy private school. When the teacher is found dead, Blue must find out what happened.
Tsukuru Tazaki once had five very close friends who expelled him from their group for no apparent reason. Years later, he tracks them down across Japan to find out what happened.