Eye of the Seahorse - The Chronicles of Lugh, #1

EVERY DAY IT GREW STRONGER. It crept across the land like a smothering vine, and at every harvest, there was more rot, diseased sheep, soured milk, and sick children. The morning of the fair, I smelled it, like thesour stink on Granda when he'd been out fishing. It had a taste too, like morning breath, no worse, like rotten fish. It seeped into our minds, kindling fights for no reason. IT GOT GRANDA, AND IT GOT ME.
It made us say and do things we didn't want to do, andif I hadn't gone to the fair, PETER WOULD STILL BE ALIVE. So begins Eye of the Seahorse, a Celtic fantasy about two rival cousins with magical abilities living in Ireland during the 1920's. Together, if they can manage to get along, they must find a way to stop the evil that is ravaging the countryside.