However the world will end, Ellis Kimball is ready for it. Her obsessive stash of survivalist essentials and general anxiety worry her family and her therapist, but she is determined to be prepared for every eventuality her overactive imagination can dream up—except the one that actually happens in Let's Call It a Doomsday.

Meanwhile, Ellis' new friend Hannah claims to know the date, the place and even the form the ultimate disaster heralding the end of the world will take. As the two unlikely friends with a shared obsession count down the final months, however, they discover more and more reasons to want to postpone The End.

Three elements help Let's Call It a Doomsday stand out among other recent young adult releases about mental illness: Ellis's survivalist knowledge, her Mormon religion and the author's detailed depiction of the Oakland, California setting. Ellis is just...