A humanoid of another system galactic has as mission to find life in other galaxies. They assign him the Milky Way and it is not able to find life until he meets with the earth.
He learns the language and the customs of the earthlings and it is able to make contact with an adolescent to which gives her a diamond that he had found in one from their visits to another planet.
This causes her problems to the youth who the help but then he notices that it begins to feel something special for her.
The things get complicated when the earth is sunk in constants threats of war. The humanoid, without intending it, it is wrapped in those activities and he should make a decision that will mark the destination of the whole humanity.