To look around at the milling human throng , one might become thoughtful. Each face is subtly unique. What does it signify? Cats and Dogs of the same breed, have the same face, same facial appearence..
So maybe the difference in the faces of humans indicate that within each human form resides a soul that was once the sum of an alien breed from an alien star, and somehow we have all ended up in a galactic zoological garden; this Earth..
the alien line subtly shape and stretch our visage, until it is a unique marker within the garden..
There has been previous stories about one race collecting other intelligent species in a zoo for observation. This story suggest we are alien souls looking out of an average fleshform. On this garden planet we orbit within an anicent space empire long dead ..