"There will never be another you" goes the jazz standard, but is it true? Have you ever thought that your spitting image might be wandering the world somewhere? What if you encountered you on the street? I would make fast tracks in the opposite direction.

The phenomenon of bilocation — or the same person appearing in two or more places at the same time — is a variation on this queasy fantasy, involving as it does a splitting rather than two separate versions. It is found in the biographies of saints, as well as the novels of horror writers.

One of the latter, by Haruka Hojo, was the inspiration for "Bilocation," Mari Asato's shocker about a woman with a bilocation that is capable of interfering with and perhaps even ending her life.