C.K. Kelly Martin
This book can be downloaded and read in Apple Books on your Mac or iOS device.
Naomi doesn't expect anything unusual from her annual family trip to visit her grandparents in Ireland. What she expects is to celebrate her thirteenth birthday, hang out with her friends Ciara and Shehan, and deal with her gran's Alzheimer's. What she finds is a country hit by an unexpected virus that rapidly infects the majority of the Irish population over the age of twenty-one.
Amnestic-Delirium Syndrome (ADS) starts off with memory loss, but the virus soon turns its victims aggravated, blank, or violent. Naomi and her friends must survive on their own, without lucid adults, cut off from the rest of the world, until a cure is found.
But there are whispers that ADS is not terrestrial, and soon Naomi and her friends learn the frightening truth: we are not alone.