This book falls into a sub-genre of memoir wonderfully exemplified by Calvin Trillin in "Remembering Denny". Like Calvin, Cossé investigates the case of a seemingly perfect classmate whose early promise led to an unsuccessful marriage and an early death, probably by suicide. Sybil was a spectacularly beautiful teenager with an incredible head of hair and a faultless profile. Adored by her mother, she was also a brilliant student. When the author started to see the cracks in Sybil's life, the 2 young women were no longer bosom friends and Cossé was too hurt by Sybil's coldness to try and understand what was happening. Later she interviewed some of Sybil's other friends as well as her mother, who revealed that Sybil's father had mental issues, and that she herself was adopted and brought up by an uncle. Unfortunately, Cossé displays none of Trillin's probing flair, and she failed to get me interested in Sybil's tragically short life. This felt more like an awkward attempt to exorcise guilt feelings than anything else.