Liz is 15 when she dies. Upon her death, she winds up in Elsewhere, the place where all the dead end up. Elsewhere is very similar to the living world, but people age backwards there. You arrive at the age you died at and slowly get younger until you become a baby again and are sent back to the world of the living to be reborn. Liz isn't happy about this. She wants to turn 16, but now that can't happen.
While the concept sounded interesting, I was left confused by how things worked exactly. Even after finishing the book, I wasn't sure how mental ages worked. At first, it seemed like the residents of Elsewhere continued to mentally age, even as the bodies get younger. We see a captain of a ship that is physically 7, but comes across as far older than that. Owen, a man who died at 26, but is physically 17 comes across more like a 35 year old than a teenager. Liz sounds like she's maturing as she grows younger. People hold jobs into the single digits. Marriage was discussed for Liz when she was physically 9. Yet, near the end of the book, we suddenly see Liz at 4 and Owen at 6 acting like the ages they look. So I just don't know what ages to consider anyone. And because of that, I don't really know what to think about the main romance between Liz and Owen.
Owen was 26 when he died, but looks 17 now. However, he never once came across as anything other than 35, which is what I had thought he'd be mentally (but now am unsure how that works). So in my mind, I was reading about a 35 year old getting involved with a 15 year old. And she definitely was 15 at least. But what came across as perhaps creepier was Owen's obsession with his still living wife that suddenly stopped upon meeting Liz. He watched his wife every week on earth and had done so for 9 years. Until he meets Liz and suddenly can't stop thinking about her and just feels drawn to her. While it may have been meant to be a nice example of moving on past your first love, it just came across as Owen jumping from one obsession to another.
The book also had random tangents that went nowhere and added nothing to the story. At one point, mermaids randomly show up for a very brief scene where we see them act incredibly cattily and talk about how small Liz's boobs are before they disappear, never to be mentioned again. I just had a moment of wondering what the heck was going on there. I still don't know.
The book had some nice things to say about life and living, but my questions over how the world worked overshadowed those sentiments for me.