Danny's brother Eli was killed overseas in the war (he enlisted after 9/11). Since then, the family's fallen apart. His dad's gotten meaner, his mom's checked out and Eli just misses his brother. He's started a "Book of the Dead," a list of famous people and how they died.
And then one summer, he meets Isabelle. She and her family (parents and younger twin siblings) have moved into town while her dad works on a project and her mom paints. Danny falls for Isabelle pretty much immediately. She's gorgeous but she's also completely unique.
This reminded me of the Stephen King short story The Body (which became the movie Stand By Me). They're both about friendship but also just as much about the ghost of an older brother (and, in both cases, a really excellent older brother). Which means that as I read this book, I kept picturing Eli as a young John Cusack. (This is not a hardship.)
While this is definitely a story about grieving (and the many ways there are to grieve), it isn't a depressing book. It's sad, obviously, and there's at least one part that will probably make you cry, but it's not like the entire book is designed to rip out your heart.
This is just as much a book about how you go on when you think you can't. And, of course, it's about friendship. Danny loves Isabelle, but I wouldn't call this a love story. Instead, it's about how the right person at the right time can change everything. (And that's just as true about the other new friend Danny meets, Walter.)
(So basically, a story about love---in all its forms---not so much a love story.)
Highly recommended.