The Lessons — Naomi Alderman

In "The Lessons" a close-knit group of friends forms at Oxford around the mercurial, charismatic figure of Mark, whose rackety trust-fund upbringing has left him as troubled and dangerously unpredictable as he is wildly promiscuous. After graduation the group fragments, each locked in his or her own suddenly adult, pedestrian world. But Mark's influence is still strong...