The Promise, Book 1 of the Ashes, Ashes series

After a nuclear bomb levels Washington, DC, a teen embarks on a treacherous 200-mile trek through a harrowing wasteland populated by desperate survivors to get his disabled sister to safety. First of the acclaimed 6 book in the Ashes, Ashes series, these adventures follow Liam Harper and his friends on a struggle for survival that tests their physical endurance, the bonds of friendship and their humanity.
Praise for the Ashes, Ashes Series

“A fresh take on the end of the world.”
“Devastating.”
“Highly recommend.”
“A story about young people… but the accuracy and horror of this fight for survival aren’t for any under 16.”
“End of everything from the point of view of two little girls and six teens—none of them are survivalists. Fast moving plot and interesting individual characters.”