The Perks of Being a Wallflower by Stephen Chbosky

The Setup
The protagonist, who identifies himself simply as Charlie, tells his story in a series of letters to an unknown recipient he refers to as “Dear friend.” He finds his first year of high school difficult because he’s being bullied – and because his good friend, Michael, committed suicide the previous spring. Also, Charlie’s existence seems heavily influenced by memories of his late Aunt Helen. Soon Charlie makes new friends: Sam, and her stepbrother, Patrick, who are two years older than him. Charlie develops a crush on Sam, but she already has a boyfriend, Craig, so Charlie starts dating Mary Elizabeth, one of Sam’s good friends.

The Twist
On his sixteenth birthday, Charlie reveals that his aunt Helen was molested as a child. Also, he feels responsible for her death because she passed away in a car accident on her way to get him a gift for his seventh birthday. He gets so depressed in the days following that he takes LSD at a party and suffers a bit of a mental breakdown from which he recovers, but his relationship with Mary Elizabeth suffers after his love for Sam is made obvious.

The Spoiler
Sam and Patrick graduate from high school, which upsets Charlie, as they will leave him behind to go to college. But after Sam breaks up with an unfaithful Craig, Charlie finally gets his chance with Sam. Just as they’re about to have intercourse (he’s a virgin, she is not) he stops her. The next day, Charlie suffers another breakdown. He ends up in the hospital, where he discovers that his Aunt Helen had molested him when he was a child; his almost-tryst with Sam must have triggered the memory. The novel ends with Charlie forgiving his Aunt Helen, and finding the strength to move on with his life.