Transfer of mitochondria between cells is a ubiquitously occurring and now universally known phenomenon. For years, researchers have been serially demonstrating that one particular new cell type can transfer its mitos to yet another particular cell type to achieve some specific metabolic goal essential to survival of the meta-host organism. But what happens when the mitochondria come from the outside world, from other members of your own species, or from a different species altogether? In addressing this very real situation, we first must look at the particulars of how and why mitos are transmitted across cell boundaries in the first place.