When neither of the only two people who know what happened can actually say — one being dead and the other having retrograde amnesia — how do you know who to believe? You don't. All you have is a lot of gossip, colored by the opinions and prejudices of the gossipers. And when said gossipers are teenage girls and/or unknown Internet commenters, everything just gets messy.

This novel does a really great job keeping the above consistent throughout, realistic without being patronizing or contemptuous. All kinds of perspectives were shown — from "I didn't know her well but I know they were best friends" to "yeah, she totally did it because she was jealous" — and in multiple forms of media, and the variety illustrated the cacophany of conflicting tales of what really happened.

I also thought the ending was really well executed.

Spoiler

Even though we never find out the truth, just as Jill may never know for sure whether or not she killed her best friend on purpose, there was a satisfying sense of closure and acceptance.