How did it turn out this way? Earths second chance

After centuries after humans left earth. It seems to be healing slowly with a steady increase of being able to have human life again. Animals seem to reappear. Humans decided to check it out only to see another civilization has taken over. One of them being a gorgeous purple male with a mission. Holt can't help but wonder more about him while also trying to live up to his father's expectations and his job.