Short story originally published in Strange Horizons and available to read online at magazine's website.
A magical accident, a terrible mistake, and a lighthouse on a promontory, high above the ocean.
You must understand: there wasn’t anything to do, at that time. You couldn’t go online, or read a book. You couldn’t check your email or read the news. So many people took up running that there were two London Marathons that year. And magic had become a primal thing – you could do it if you knew the working so well it was part of your body; you couldn’t look it up. And I remember people didn’t even do that: they were frightened, because of me, because of what I had done.