There’s a special sort of satisfaction I get out of answering the question “What is that book about?” with “The end of the world.” And that’s what Sara Grant’s Half Lives deals with, at least in part. The other part deals with the beginning of the world. Sound intriguing? It is.

We meet Icie (short for Isis) first, the daughter of brilliant, wealthy parents who send her an urgent 911 text out of the blue. They say they’ve learned that a bioterrorist attack is imminent, and they need to get to an abandoned bunker in Las Vegas. The bunker was at one point planned to be used as a nuclear waste disposal facility, but those plans were scrapped, making it the perfect place to wait out the end of the world. Isie and her parents become separated, and Isie finds herself hiding out in the bunker with three other companions she picked up along the way while the apocalype rages outside.

Generations later, we meet Beckett. He’s only a teenager, but he’s the leader of a group of people who live on the Mountain and worship the great I AM. One day, he meets a girl who lives in Vega, the destroyed city they can see from the Mountain. The girl, Greta, is confused by the culture Beckett belongs to, with their strange Sayings, odd nomenclature, and refusal to leave the Mountain. When members of Beckett’s people discover he’s had dealings with Greta, violence ensues between the two peoples.

Isie’s story is an edge of your seat thriller, whereas Beckett’s is a puzzler, causing you to think about each and every detail as it’s revealed to determine how it connects to Isie’s story. I loved them both almost equally, with Isie’s story barely edging out Beckett’s. But really, they’re in conversation with each other, and they need to be read in alternating chapters as they’re laid out. (I read a review where the reader said she read all Isie’s chapters, then went back and read all of Beckett’s. Please don’t do this. Well, I suppose you can if you want, but you’d be cheating yourself.)

Both Isie’s and Beckett’s stories are about what it means to survive, though in different ways. Isie is not your stereotypical do-gooder survivor, helping other sufferers with little to no questions or hesitation. A lot of the times she’s selfish, she thinks of herself first and foremost, and I love that Grant doesn’t make a sweeping judgment about her for it. Icie’s allowed to be human at the end of the world, allowed to think that the 13 year old kid who’s attached himself to her is annoying, allowed to hate the fact that her companions smell bad, allowed to want to grab some happiness where she can even if it means someone else may go without. I’m tired of self-sacrificial females in fiction, and while Isie certainly sacrifices a lot, she’s not sacrificial. I think there’s a difference.

While Isie’s story may be more gripping, Beckett’s is more thoughtful, and it’s much less about character than it is about ideas – what it means to be a survivor of survivors, and how we honor and interpret the past. Any teen who’s ever thought about how their own leavings may be interpreted by future generations will love what Grant’s done with Beckett’s culture. It could have been gimmicky, but instead it’s fascinating. It’s also funny, but not in a way that undercuts the seriousness of the situation. From the outset, we know Beckett’s story is linked to Isie’s, but deciphering the details is what makes it such an interesting read. The plot of his story is not nearly as important as what his story means about people’s reliance on the past, on their faith, and on whatever connection they can muster to those who came before.

The idea for Half Lives was inspired by a news story about nuclear waste disposal facilities, but that aspect of the book isn’t what kept me thinking about it for days afterward, though that’s certainly an important issue to consider. Instead, I was left wondering what my own legacy would be, if any, and what messages I could send, if any, to those who come after me. A couple reviews I read questioned if this was an issue teens could relate to, but I don’t doubt that they can and do.

Half Lives is a standout in a crowded field. I cried twice (not great gulping sobs, since I was in public, but I sure wanted to), which I’m pretty sure I haven’t done since Harry Potter 7 (don’t quote me on that). It’s not strictly a dystopia, though it certainly has a lot of the same appeal factors. If you’re burned out on the subgenre but are still hoping to find something that can inject new life into it, this is your book.

Review copy received from the publisher. Half Lives will be published July 9.