This story is a surprisingly easy read as is all of Rosen's stories. Even though the subject matter is something that most people don't think about, it's dealt with in a compasionate way.
Meg is about to jump of a cliff as her undiagnosed mental illness makes her not want to live any more. Poppy comes across her and befriends her and helps her to understand her illness. It sounds depressing but isn't. It does pull at your heart at times.
Before discovering Rosen, I'd not thought about mental illness, but I feel Rosen helps you to understand it.
I'd read this as part of Seesaw which has to be one of my Books of the Year.