Joseph Wurtenbaugh's Old Soul is a fantastic Kindle Single. I tore through this short story, unwilling to put it down.
A tale of survival, change and perhaps the source of that eerie deja-vu that plagues you; Wurtenbaugh tells the story of That-Which-Had-Been. We follow a microbiological organism as it journeys from its dying host to another, and another, seeking a new home.
I can't recommend Old Soul highly enough. For .99 this is a do not miss Kindle Single!