Ash

"Abrahams tells the story of four college friends, an ex-con, a lonely fry cook, and a secretive group of prepared civilians as they each battle to survive in southern California after a series of nuclear attacks. Theirs is a gray world covered in ash and nuclear fallout." — quoted from this book's product page on Amazon as of 2018-06-07.

•Each book in this series has the same characters, but set in alternate universes with alternate apocalypses.