Struggle for the future

Reasonable creatures with an indigo color aura.
The only one who is able to activate the "lighthouses" are the portals remaining from the ancient, a long time ago who had left our galaxy race.
Carriers of Indigo Aura is very, very small.
For each of them, it does not matter, humanoid or not, the most powerful of space civilizations - the free federation and the Alliance Kriov - lead a real war.
But one day, the warring "alien" becomes known: on a small, backward planet the land lives the many "Indigo".
Earthman - obviously not rivals to neither crucible or federals.
But if the Free Federation intends to enter with earthlings in contact and conclude a friendly union with them, then the warlike destroyer simply intends to win our planet and turn people into slaves - living keys for "lighthouses"